Re: [CentOS] Jumbo frames problem with Realtek NICs?
On 6/24/11, Christopher Chan wrote: > On Friday, June 24, 2011 01:20 AM, Emmanuel Noobadmin wrote: >> First bottleneck was discovering the max MTU allowed on these is 7K >> instead of 9K but googling seems to indicate that the RTL8168B is only >> capable of 4K frames. > > Yeah, the 8168C goes up to 7k. Some 8168B go up to 6k. In cases like this where there are conflicting sources of information regarding the max MTU of a NIC, what would be the correct way to determine the actual max MTU? I figured the 7K limit basically by doing a binary search with the ifconfig mtu commands. But is the this figure simply what the driver will accept for the controller it identified or is that the actual hardware limit? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
On Thursday 23 June 2011 20:23, Always Learning wrote: > Currently running 5.6 and would like a two set DVD of that version. > However none of the mirrors offer pure DVDs only Torrent versions > which involve the possibility of bits being tampered with and things > leaving my servers without explicit knowledge and authority. Some of the mirrors have DVD images available for direct download. For example, at http://www.centos.org/modules/tinycontent/index.php?id=30 , some mirrors are indicated as having "Direct DVD Downloads". I agree with John that the argument about torrents not being "virgin" is complete nonsense. You get the torrent file from one of the mirrors, and that's just as secure are getting an ISO image from one of the mirrors. Once you've downloaded the DVD image using BitTorrent, you can check it against the checksums in the release announcement in exactly the same way as if you downloaded the DVD image itself from a mirror. -- Yves Bellefeuille "La Esperanta Civito ne rifuzas anticipe la kunlaboron de erarintoj, se ili konscias pri sia eraro." -- Heroldo Komunikas, n-ro 473. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
> Thank you. I note your reservation "as long as you get the > original .torrent file from a reliable source." I don't know what this > exactly means." > > I prefer virgin copies. right now, you get that virgin copy off one or another of the centos mirrors, and check its md5 against the master copy on the centos site? so... get the torrent file from the same place. verify the .torrent control file's md5 before starting the torrent. when the torrent has finished transferring, you can also verify the md5's of the ISO files it contains. but... the DVD ISO's are on select mirrors, such as http://mirrors.kernel.org/centos/5.6/isos/x86_64/ -- john r pierceN 37, W 122 santa cruz ca mid-left coast ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On 6/23/11 8:44 PM, Marian Marinov wrote: > > I have compared the performance of both XFS and Ext4. And since I use those > big machines for backups, for me the write performance was very important. > XFS was almost twice slower. Twice slower? At what kind of operations? I don't think any filesystem should have that much overhead at things like writing large files. -- Les Mikesell lesmikes...@gmail.com ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Friday 24 June 2011 04:34:20 Smithies, Russell wrote: > We have a single 27TB partition (35 x 1TB drives as RAID5+0 in an HP > MDS600), just formatted it xfs and had no problems with it so far. It's > used as scratch space so not too concerned about performance. > > --Russell > I have compared the performance of both XFS and Ext4. And since I use those big machines for backups, for me the write performance was very important. XFS was almost twice slower. But lets leave XFS alone :) Ext4 is the way to go :) Marian signature.asc Description: This is a digitally signed message part. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
We have a single 27TB partition (35 x 1TB drives as RAID5+0 in an HP MDS600), just formatted it xfs and had no problems with it so far. It's used as scratch space so not too concerned about performance. --Russell > -Original Message- > From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On > Behalf Of Marian Marinov > Sent: Friday, 24 June 2011 7:48 a.m. > To: CentOS mailing list > Subject: Re: [CentOS] ext4 in CentOS 5.6? > > On Thursday 23 June 2011 22:31:28 PJ wrote: > > On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: > > > On Thursday 23 June 2011 19:16:37 PJ wrote: > > >> I'm sure many are running ext4 FS's in production, but just want > to > > >> be re-assured that there are not currently any major issues before > > >> starting a new project that looks like it will be using ext4. > > >> > > >> I've previously been using xfs but the software for this project > > >> requires ext3/ext4. > > >> > > >> I'm always very cautious before jumping onto a new FS, (new in the > > >> sense it is officially supported now) > > >> > > >> Thanks in advance! > > > > > > I'm running some 50 servers with ext4 each server has 2x15TB ext4 > > > partitions. I haven't had an issue with that setup. The first > server > > > was setup 3 years ago. It is quite faster then XFS in terms of > write > > > performance and thus far reliable without any major problem. > > > > > > Keep in mind that user land tools are limited and the biggest > > > partition you can create with them at the moment is 16TB. You can > > > recompile the tools and remove this limitation if that is a problem > for you. > > > > > > Regards, > > > Marian Marinov > > > > Thanks for all the great replies everyone. > > > > I've got an 18TB partition - the limit is 16TB even in x86_64? > > Yes. At least it was so, last year. I haven't checked recently. And I > don't have a spare machine to repartition for the test. > We have a 30TB RAID6 array and I was really annoyed that I had to make > two partitions to utilze the whole space. > > The wiki pages are still not updated: > http://en.wikipedia.org/wiki/Comparison_of_file_systems > https://ext4.wiki.kernel.org/index.php/Ext4_Howto > > NOTE: Although very large fileystems are on ext4's feature list, > current e2fsprogs currently still limits the filesystem size to 2^32 > blocks (16TiB for a 4KiB block filesystem). Allowing filesystems larger > than 16T is one of the very next high-priority features to complete for > ext4. > > > > > ___ > > CentOS mailing list > > CentOS@centos.org > > http://lists.centos.org/mailman/listinfo/centos > > -- > Best regards, > Marian Marinov === Attention: The information contained in this message and/or attachments from AgResearch Limited is intended only for the persons or entities to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipients is prohibited by AgResearch Limited. If you have received this message in error, please notify the sender immediately. === ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
Hi Edo, > > Currently running 5.6 and would like a two set DVD of that version. > > However none of the mirrors offer pure DVDs only Torrent versions which > > involve the possibility of bits being tampered with and things leaving > > my servers without explicit knowledge and authority. > > > > None of the CD / DVD sellers I have contacted can offer Centos 5.6 DVDs > > because, they say, they can't get a virgin 5.6 DVD only Torrent. > Have you tried the Asian mirrors? > > http://www.centos.org/modules/tinycontent/index.php?id=32 > > For example, > > http://ftp.riken.jp/Linux/centos/5.6/isos/x86_64/ > > HTH, Thank you very much. It does help enormously. I am most grateful. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
On Thu, 2011-06-23 at 18:00 -0700, John R Pierce wrote: > > Currently running 5.6 and would like a two set DVD of that version. > > However none of the mirrors offer pure DVDs only Torrent versions which > > involve the possibility of bits being tampered with and things leaving > > my servers without explicit knowledge and authority. > > > > None of the CD / DVD sellers I have contacted can offer Centos 5.6 DVDs > > because, they say, they can't get a virgin 5.6 DVD only Torrent. > > that argument is a total red herring. > > torrents are digitally signed and protected with MD5 checksums on each > block, they can't be tampered with as long as you get the original > .torrent file from a reliable source. Thank you. I note your reservation "as long as you get the original .torrent file from a reliable source." I don't know what this exactly means." I prefer virgin copies. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
Hi, On Friday, June 24, 2011 at 9:23 AM, Always Learning wrote: [ ... ] > Currently running 5.6 and would like a two set DVD of that version. > However none of the mirrors offer pure DVDs only Torrent versions which > involve the possibility of bits being tampered with and things leaving > my servers without explicit knowledge and authority. > > None of the CD / DVD sellers I have contacted can offer Centos 5.6 DVDs > because, they say, they can't get a virgin 5.6 DVD only Torrent. Have you tried the Asian mirrors? http://www.centos.org/modules/tinycontent/index.php?id=32 For example, http://ftp.riken.jp/Linux/centos/5.6/isos/x86_64/ HTH, -- - Edo - mailto:ml2ed...@gmail.com “A wise person will listen and take in more instruction ...” —Proverbs 1:5 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
> Currently running 5.6 and would like a two set DVD of that version. > However none of the mirrors offer pure DVDs only Torrent versions which > involve the possibility of bits being tampered with and things leaving > my servers without explicit knowledge and authority. > > None of the CD / DVD sellers I have contacted can offer Centos 5.6 DVDs > because, they say, they can't get a virgin 5.6 DVD only Torrent. that argument is a total red herring. torrents are digitally signed and protected with MD5 checksums on each block, they can't be tampered with as long as you get the original .torrent file from a reliable source. -- john r pierceN 37, W 122 santa cruz ca mid-left coast ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] No DVD Mirrors - Only Torrent
P.S. Johnny, Thank you for Seahorse. Much appreciated. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] No DVD Mirrors - Only Torrent
I love Centos. Have in on my data centre servers, my home servers, my laptop and my netbook. Yes there are serious and continuing security concerns relating to Gnome and KDE but they are not Centos. Currently running 5.6 and would like a two set DVD of that version. However none of the mirrors offer pure DVDs only Torrent versions which involve the possibility of bits being tampered with and things leaving my servers without explicit knowledge and authority. None of the CD / DVD sellers I have contacted can offer Centos 5.6 DVDs because, they say, they can't get a virgin 5.6 DVD only Torrent. FreeBSD 8.2 (the latest) offers a virgin 1 DVD download. The whole distribution is about 4 DVDs. Can Centos offer a virgin 1 DVD download of 5.6 for those of us who are unhappy about slow Torrent, the possibility of tampering and the traffic out of our machines ? BY THE WAY, a very BIG and GRATEFUL THANK YOU to the EXCELLENT TEAM that gave us the wonderful Centos 5.6. Very much appreciated and if KBS and the others ever venture out of Kent and London a bit northwards but south of Watford I would be delighted to buy him and the others several rounds of drinks. It makes me want to write an application for Linux. -- With best regards, Paul. England, EU. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
On Friday, June 24, 2011 01:20 AM, Emmanuel Noobadmin wrote: > First bottleneck was discovering the max MTU allowed on these is 7K > instead of 9K but googling seems to indicate that the RTL8168B is only > capable of 4K frames. Yeah, the 8168C goes up to 7k. Some 8168B go up to 6k. > > I assumed 4K would still be better than nothing but unfortunately > bumping up the MTU to anything else but 1.5K caused the file transfers > (using NFS for easy testing), to hang at random points or more > accurate slow to a crawl. I have the crap enabled in Windows and it works there...but on an old server running OpenIndiana the driver refuses to enable jumbo frames for the particular chipset that the board has which is incidentally a 8168B. > > Checking the syslog, I discovered warnings that increasing MTU with > this adapter may cause problems. > > Searching around, it seems to be a common problem but there doesn't > appear to be any clear cut fix, including some suggestions to use a > third party driver. > > Does anybody know of a proven solution or is the Realtek chip itself > irrevocably broken/bugged that anything above the default 1500 will > simply not work? Using realtek's own drivers on Windows seem to be okay...not sure about Linux and other platforms. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On 6/23/2011 12:16 PM, PJ wrote: > I'm sure many are running ext4 FS's in production, but just want to be > re-assured that there are not currently any major issues before > starting a new project that looks like it will be using ext4. > > I've previously been using xfs but the software for this project > requires ext3/ext4. > > I'm always very cautious before jumping onto a new FS, (new in the > sense it is officially supported now) > Works fine here. I think you would have been jumping the gun if you were asking this in 2009, but by now it's well understood and the tools are fine in 2011. It's been around long enough. I use it anywhere that I have multi-gigabyte files that need to be handled with speed (deleting large files on ext3 is an exercise in patience) or where I have lots and lots of little files (which ext3 sometimes had trouble with). ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Jun 23, 2011, at 12:16 PM, PJ wrote: > I'm sure many are running ext4 FS's in production, but just want to be > re-assured that there are not currently any major issues before > starting a new project that looks like it will be using ext4. > > I've previously been using xfs but the software for this project > requires ext3/ext4. > > I'm always very cautious before jumping onto a new FS, (new in the > sense it is officially supported now) > > Thanks in advance! I've seen some interesting behavior from "df" on an ext4 file system just today, on a fully-patched CentOS 5.6 system. I was running "watch -d -n 1 df -b G" while copying several TB around. One second, "df" would report that 1600 GB were in use. The next, I'd be up to 2500 GB; and then, over 3000 GB. Then it would drop down to 1200 GB and start counting up again. The amount of disk space actually in use as reported by "du" was closer to 600 GB. I should mention, that is just a sample of the observed behavior. It seemed like "df" would start this fluctuation cycle at the correct number, and I would sometimes catch it there; but it would be off by a couple TB before it re-cycled. Is this something anyone else has seen? This was a new 10 TB file system formatted for ext4 directly, rather than formatted as ext3 and converted to ext4. I've also noticed that I seem to lose more disk space to general overhead than I did with ext3. I'm not talking about the space reserved for root - I've set "-m 0" in both cases. I mean that on an 8 GB logical volume, the formatted size would be 7.8 GB under ext3, versus 7.5 GB with ext4.A 16 GB file system in ext3 would be 15 GB in ext4. Does that match expectations? Thanks, James ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thu, Jun 23, 2011 at 12:49 PM, Marian Marinov wrote: > On Thursday 23 June 2011 22:41:50 PJ wrote: >> On Thu, Jun 23, 2011 at 12:31 PM, PJ wrote: >> > On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: >> >> On Thursday 23 June 2011 19:16:37 PJ wrote: >> >>> I'm sure many are running ext4 FS's in production, but just want to be >> >>> re-assured that there are not currently any major issues before >> >>> starting a new project that looks like it will be using ext4. >> >>> >> >>> I've previously been using xfs but the software for this project >> >>> requires ext3/ext4. >> >>> >> >>> I'm always very cautious before jumping onto a new FS, (new in the >> >>> sense it is officially supported now) >> >>> >> >>> Thanks in advance! >> >> >> >> I'm running some 50 servers with ext4 each server has 2x15TB ext4 >> >> partitions. I haven't had an issue with that setup. The first server >> >> was setup 3 years ago. It is quite faster then XFS in terms of write >> >> performance and thus far reliable without any major problem. >> >> >> >> Keep in mind that user land tools are limited and the biggest partition >> >> you can create with them at the moment is 16TB. You can recompile the >> >> tools and remove this limitation if that is a problem for you. >> >> >> >> Regards, >> >> Marian Marinov >> > >> > Thanks for all the great replies everyone. >> > >> > I've got an 18TB partition - the limit is 16TB even in x86_64? >> >> Answering my own question yes, 16TB is the limit. >> Has anyone here successfully compiled their own version of e2fsprogs >> that works over 16TB? >> >> Looking at https://ext4.wiki.kernel.org/index.php/Ext4_Howto it says: >> "The code to create file systems bigger than 16 TiB is, at the time of >> writing this article, not in any stable release of e2fsprogs. It will >> be in future releases." >> >> Not sure if the wiki is out of date or not... > > What I have seen is only a alpha/beta quality code that adds this > functionality. > > I would not suggest that you use those patches. At least not on a production > machine. I only wanted to mention that there is such code... not that it is > actually working :) > > Marian >> >> Thanks! Thanks Marian, it looks like it's 2 x 9TB partitions for me, what a pain in the ass! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thursday 23 June 2011 22:41:50 PJ wrote: > On Thu, Jun 23, 2011 at 12:31 PM, PJ wrote: > > On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: > >> On Thursday 23 June 2011 19:16:37 PJ wrote: > >>> I'm sure many are running ext4 FS's in production, but just want to be > >>> re-assured that there are not currently any major issues before > >>> starting a new project that looks like it will be using ext4. > >>> > >>> I've previously been using xfs but the software for this project > >>> requires ext3/ext4. > >>> > >>> I'm always very cautious before jumping onto a new FS, (new in the > >>> sense it is officially supported now) > >>> > >>> Thanks in advance! > >> > >> I'm running some 50 servers with ext4 each server has 2x15TB ext4 > >> partitions. I haven't had an issue with that setup. The first server > >> was setup 3 years ago. It is quite faster then XFS in terms of write > >> performance and thus far reliable without any major problem. > >> > >> Keep in mind that user land tools are limited and the biggest partition > >> you can create with them at the moment is 16TB. You can recompile the > >> tools and remove this limitation if that is a problem for you. > >> > >> Regards, > >> Marian Marinov > > > > Thanks for all the great replies everyone. > > > > I've got an 18TB partition - the limit is 16TB even in x86_64? > > Answering my own question yes, 16TB is the limit. > Has anyone here successfully compiled their own version of e2fsprogs > that works over 16TB? > > Looking at https://ext4.wiki.kernel.org/index.php/Ext4_Howto it says: > "The code to create file systems bigger than 16 TiB is, at the time of > writing this article, not in any stable release of e2fsprogs. It will > be in future releases." > > Not sure if the wiki is out of date or not... What I have seen is only a alpha/beta quality code that adds this functionality. I would not suggest that you use those patches. At least not on a production machine. I only wanted to mention that there is such code... not that it is actually working :) Marian > > Thanks! > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos signature.asc Description: This is a digitally signed message part. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thursday 23 June 2011 22:31:28 PJ wrote: > On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: > > On Thursday 23 June 2011 19:16:37 PJ wrote: > >> I'm sure many are running ext4 FS's in production, but just want to be > >> re-assured that there are not currently any major issues before > >> starting a new project that looks like it will be using ext4. > >> > >> I've previously been using xfs but the software for this project > >> requires ext3/ext4. > >> > >> I'm always very cautious before jumping onto a new FS, (new in the > >> sense it is officially supported now) > >> > >> Thanks in advance! > > > > I'm running some 50 servers with ext4 each server has 2x15TB ext4 > > partitions. I haven't had an issue with that setup. The first server was > > setup 3 years ago. It is quite faster then XFS in terms of write > > performance and thus far reliable without any major problem. > > > > Keep in mind that user land tools are limited and the biggest partition > > you can create with them at the moment is 16TB. You can recompile the > > tools and remove this limitation if that is a problem for you. > > > > Regards, > > Marian Marinov > > Thanks for all the great replies everyone. > > I've got an 18TB partition - the limit is 16TB even in x86_64? Yes. At least it was so, last year. I haven't checked recently. And I don't have a spare machine to repartition for the test. We have a 30TB RAID6 array and I was really annoyed that I had to make two partitions to utilze the whole space. The wiki pages are still not updated: http://en.wikipedia.org/wiki/Comparison_of_file_systems https://ext4.wiki.kernel.org/index.php/Ext4_Howto NOTE: Although very large fileystems are on ext4's feature list, current e2fsprogs currently still limits the filesystem size to 2^32 blocks (16TiB for a 4KiB block filesystem). Allowing filesystems larger than 16T is one of the very next high-priority features to complete for ext4. > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos -- Best regards, Marian Marinov signature.asc Description: This is a digitally signed message part. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thu, Jun 23, 2011 at 12:31 PM, PJ wrote: > On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: >> On Thursday 23 June 2011 19:16:37 PJ wrote: >>> I'm sure many are running ext4 FS's in production, but just want to be >>> re-assured that there are not currently any major issues before >>> starting a new project that looks like it will be using ext4. >>> >>> I've previously been using xfs but the software for this project >>> requires ext3/ext4. >>> >>> I'm always very cautious before jumping onto a new FS, (new in the >>> sense it is officially supported now) >>> >>> Thanks in advance! >> >> I'm running some 50 servers with ext4 each server has 2x15TB ext4 partitions. >> I haven't had an issue with that setup. The first server was setup 3 years >> ago. >> It is quite faster then XFS in terms of write performance and thus far >> reliable without any major problem. >> >> Keep in mind that user land tools are limited and the biggest partition you >> can create with them at the moment is 16TB. You can recompile the tools and >> remove this limitation if that is a problem for you. >> >> Regards, >> Marian Marinov > > Thanks for all the great replies everyone. > > I've got an 18TB partition - the limit is 16TB even in x86_64? > Answering my own question yes, 16TB is the limit. Has anyone here successfully compiled their own version of e2fsprogs that works over 16TB? Looking at https://ext4.wiki.kernel.org/index.php/Ext4_Howto it says: "The code to create file systems bigger than 16 TiB is, at the time of writing this article, not in any stable release of e2fsprogs. It will be in future releases." Not sure if the wiki is out of date or not... Thanks! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thu, Jun 23, 2011 at 1:07 PM, Marian Marinov wrote: > On Thursday 23 June 2011 19:16:37 PJ wrote: >> I'm sure many are running ext4 FS's in production, but just want to be >> re-assured that there are not currently any major issues before >> starting a new project that looks like it will be using ext4. >> >> I've previously been using xfs but the software for this project >> requires ext3/ext4. >> >> I'm always very cautious before jumping onto a new FS, (new in the >> sense it is officially supported now) >> >> Thanks in advance! > > I'm running some 50 servers with ext4 each server has 2x15TB ext4 partitions. > I haven't had an issue with that setup. The first server was setup 3 years > ago. > It is quite faster then XFS in terms of write performance and thus far > reliable without any major problem. > > Keep in mind that user land tools are limited and the biggest partition you > can create with them at the moment is 16TB. You can recompile the tools and > remove this limitation if that is a problem for you. > > Regards, > Marian Marinov Thanks for all the great replies everyone. I've got an 18TB partition - the limit is 16TB even in x86_64? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] how to find out what is causing high mysql cpu load
Hi all, I have a CentOS 5.6 xen domU that is used for hosting several Apache virtual hosts that use MySQL. Lately, this domU has been having performance issues and I've noticed web pages loaded from this server opening slower than usual. When I run 'top' I see mysqld constantly consuming 10-60% of CPU. sar reports average of 10-20 for %user, 5 for %system, 0.2 for %iowait and 10-20 for %steal When looking at 'xm top' in dom0 (running also CentOS 5.6) most of the other domUs have CPU(%) near zero and only this domU is reported to consume CPU more than 10%. The strange thing is, that when I run 'mytop', I do not see that many queries: I see avg of 4 users "sleeping" and occasionally some other user running a query. qps is mostly 0. No slow queries. Key efficiency is 97%. Here is my /etc/my.cnf: max_connections = 300 max_user_connections = 300 wait_timeout = 180 Nothing interesting in /var/log/mysqld.log. I tried rebooting both the dom0 and the domU which made no difference. Questions: 1. How to debug further why mysqld is taking so much cpu? 2. If I've understood correctly, the high steal% value reported by sar means that the hypervisor is giving cpu time for some other domU. How to find out why and where this cpu time is stolen to? Regards, Peter ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
- Original Message - > I can not say I had any problems with Realtek NIC's. I operate a small > WISP and I am active in StarOS wireless network reouter community. > Most > of us there agree that when you have problems with NICS like 3Com or > even Intel, you can always use Realtek NIC's for X86-PC routers. > > Try ElRepo driver and please report if that helps. I would like to > know > your experience with ElRepo driver. > Realtek NICs and drivers are typically quite ubiquitous in that they work on nearly every platform. This is especially true with the RTL-8139(+) series. However, that doesn't make them a quality interface. :) I'm sure there are plenty of installations where these NICs work great without problems. In fact, now that I think about it, my home router uses two RTL-8189 interfaces on FreeBSD 8.1 without problems. They certainly have a proper spot in the network (low throughput, etc). I just wouldn't want them in my servers, especially not for ones expected of high performance or storage related tasks. --Tim ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
Tim Nelson wrote: > - Original Message - >> I was trying to do some performance testing between using iSCSI on the >> host as a diskfile to a guest vs the VM guest using the iSCSI device >> directly. >> >> However, in the process of trying to establish a baseline performance >> figure, I started increasing the MTU settings on the PCI-express NICs >> with RTL8168B chips. >> >> First bottleneck was discovering the max MTU allowed on these is 7K >> instead of 9K but googling seems to indicate that the RTL8168B is only >> capable of 4K frames. >> >> I assumed 4K would still be better than nothing but unfortunately >> bumping up the MTU to anything else but 1.5K caused the file transfers >> (using NFS for easy testing), to hang at random points or more >> accurate slow to a crawl. >> >> Checking the syslog, I discovered warnings that increasing MTU with >> this adapter may cause problems. >> >> Searching around, it seems to be a common problem but there doesn't >> appear to be any clear cut fix, including some suggestions to use a >> third party driver. >> >> Does anybody know of a proven solution or is the Realtek chip itself >> irrevocably broken/bugged that anything above the default 1500 will >> simply not work? > > Realtek NICs are known to be some of the poorest interfaces available. A > quality Intel or Broadcom NIC will set you back very little in terms of cost. > Just replace it and be done. :) > > --Tim > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > > I can not say I had any problems with Realtek NIC's. I operate a small WISP and I am active in StarOS wireless network reouter community. Most of us there agree that when you have problems with NICS like 3Com or even Intel, you can always use Realtek NIC's for X86-PC routers. Try ElRepo driver and please report if that helps. I would like to know your experience with ElRepo driver. Ljubomir ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
- Original Message - > I was trying to do some performance testing between using iSCSI on the > host as a diskfile to a guest vs the VM guest using the iSCSI device > directly. > > However, in the process of trying to establish a baseline performance > figure, I started increasing the MTU settings on the PCI-express NICs > with RTL8168B chips. > > First bottleneck was discovering the max MTU allowed on these is 7K > instead of 9K but googling seems to indicate that the RTL8168B is only > capable of 4K frames. > > I assumed 4K would still be better than nothing but unfortunately > bumping up the MTU to anything else but 1.5K caused the file transfers > (using NFS for easy testing), to hang at random points or more > accurate slow to a crawl. > > Checking the syslog, I discovered warnings that increasing MTU with > this adapter may cause problems. > > Searching around, it seems to be a common problem but there doesn't > appear to be any clear cut fix, including some suggestions to use a > third party driver. > > Does anybody know of a proven solution or is the Realtek chip itself > irrevocably broken/bugged that anything above the default 1500 will > simply not work? Realtek NICs are known to be some of the poorest interfaces available. A quality Intel or Broadcom NIC will set you back very little in terms of cost. Just replace it and be done. :) --Tim ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
Just another happy camper here. We have ext4 for some high-volume servers and have experienced no operational problems. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
PJ writes: > I'm sure many are running ext4 FS's in production, but just want to be > re-assured that there are not currently any major issues before > starting a new project that looks like it will be using ext4. > > I've previously been using xfs but the software for this project > requires ext3/ext4. > > I'm always very cautious before jumping onto a new FS, (new in the > sense it is officially supported now) > > Thanks in advance! > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > I use it in production wih several TB on top of mdraid+lvm, no problems so far. Nice and fast; love the online resize feature. Go for it. -- Nux! www.nux.ro ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] OT: DHCP address pool for specific MAC manufacturer
On 06/23/2011 06:29 AM, Steven Tardy wrote:
> did something similar recently...
>
> dhcpd.conf
> --
> class "VMware" { match if ( substring(hardware,1,3) = 00:50:56 ); }
> subnet 10.1.1.224 netmask 255.255.255.240 {
> #other subnet specific stuff here
> pool { allow members of "VMware"; range 10.1.1.229 10.1.1.230; }
> pool { deny members of "VMware"; range 10.1.1.236 10.1.1.237; }
> }
> --
>
> On 06/22/11 21:44, Raymond Lillard wrote:
>> Dear CentOS,
>>
>> This is somewhat off-topic, but I do hope to implement this on
>> a CentOS system, so here goes...
>>
>> I would like to be able to setup a dhcpd (or like) daemon to
>> maintain two IP address pools. One for devices whose leading
>> three octets of the client MAC address are specified and the
>> other for all other clients. Both pools would be a defined
>> range on a commmon /24 subnet. There a several static IP
>> devices also on this net (servers, printer, etc...). At no
>> time would there be more than a dozen of the specified MAC
>> range devices active.
Sorry for the noise. When I looked at dhcp, it was on a machine
with a seriously out-of-date version.
Thanks,
Ray
___
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
Emmanuel Noobadmin wrote: > Does anybody know of a proven solution or is the Realtek chip itself > irrevocably broken/bugged that anything above the default 1500 will > simply not work? > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > > Try driver from ElRepo: http://elrepo.org/tiki/tiki-index.php?page=kmod-r8168 Ljubomir ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
On 6/24/11, Tim Nelson wrote: > Realtek NICs are known to be some of the poorest interfaces available. A > quality Intel or Broadcom NIC will set you back very little in terms of > cost. Just replace it and be done. :) I was afraid that might be the case (already had two Intel NICs in the shopping cart to be honest) but was hoping I didn't have to waste time explaining why the plentiful Realtek NICs around cannot be used for testing. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Jumbo frames problem with Realtek NICs?
On 06/23/2011 01:28 PM, Tim Nelson wrote: > - Original Message - >> I was trying to do some performance testing between using iSCSI on the >> host as a diskfile to a guest vs the VM guest using the iSCSI device >> directly. >> >> However, in the process of trying to establish a baseline performance >> figure, I started increasing the MTU settings on the PCI-express NICs >> with RTL8168B chips. >> >> First bottleneck was discovering the max MTU allowed on these is 7K >> instead of 9K but googling seems to indicate that the RTL8168B is only >> capable of 4K frames. >> >> I assumed 4K would still be better than nothing but unfortunately >> bumping up the MTU to anything else but 1.5K caused the file transfers >> (using NFS for easy testing), to hang at random points or more >> accurate slow to a crawl. >> >> Checking the syslog, I discovered warnings that increasing MTU with >> this adapter may cause problems. >> >> Searching around, it seems to be a common problem but there doesn't >> appear to be any clear cut fix, including some suggestions to use a >> third party driver. >> >> Does anybody know of a proven solution or is the Realtek chip itself >> irrevocably broken/bugged that anything above the default 1500 will >> simply not work? > > Realtek NICs are known to be some of the poorest interfaces available. A > quality Intel or Broadcom NIC will set you back very little in terms of cost. > Just replace it and be done. :) > > --Tim I second this. I switched out for fairly inexpensive Intel Pro/1000CT adapters. They're to be had for ~$30~40 in Canada and work perfectly at 9kb JFs. Realtek is really built down to cost, and is not viable outside of basic web browsing, imho. -- Digimer E-Mail: digi...@alteeve.com Freenode handle: digimer Papers and Projects: http://alteeve.com Node Assassin: http://nodeassassin.org "I feel confined, only free to expand myself within boundaries." ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] Jumbo frames problem with Realtek NICs?
I was trying to do some performance testing between using iSCSI on the host as a diskfile to a guest vs the VM guest using the iSCSI device directly. However, in the process of trying to establish a baseline performance figure, I started increasing the MTU settings on the PCI-express NICs with RTL8168B chips. First bottleneck was discovering the max MTU allowed on these is 7K instead of 9K but googling seems to indicate that the RTL8168B is only capable of 4K frames. I assumed 4K would still be better than nothing but unfortunately bumping up the MTU to anything else but 1.5K caused the file transfers (using NFS for easy testing), to hang at random points or more accurate slow to a crawl. Checking the syslog, I discovered warnings that increasing MTU with this adapter may cause problems. Searching around, it seems to be a common problem but there doesn't appear to be any clear cut fix, including some suggestions to use a third party driver. Does anybody know of a proven solution or is the Realtek chip itself irrevocably broken/bugged that anything above the default 1500 will simply not work? ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
On Thursday 23 June 2011 19:16:37 PJ wrote: > I'm sure many are running ext4 FS's in production, but just want to be > re-assured that there are not currently any major issues before > starting a new project that looks like it will be using ext4. > > I've previously been using xfs but the software for this project > requires ext3/ext4. > > I'm always very cautious before jumping onto a new FS, (new in the > sense it is officially supported now) > > Thanks in advance! I'm running some 50 servers with ext4 each server has 2x15TB ext4 partitions. I haven't had an issue with that setup. The first server was setup 3 years ago. It is quite faster then XFS in terms of write performance and thus far reliable without any major problem. Keep in mind that user land tools are limited and the biggest partition you can create with them at the moment is 16TB. You can recompile the tools and remove this limitation if that is a problem for you. Regards, Marian Marinov signature.asc Description: This is a digitally signed message part. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] ext4 in CentOS 5.6?
PJ wrote: > I'm sure many are running ext4 FS's in production, but just want to be > re-assured that there are not currently any major issues before > starting a new project that looks like it will be using ext4. > > I've previously been using xfs but the software for this project > requires ext3/ext4. > > I'm always very cautious before jumping onto a new FS, (new in the > sense it is officially supported now) > > Thanks in advance! > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > > I can say if I have ext4 partitions on the production server, but my personal desktop is running ext4 partitions on secondary HDD on top of the RAID1 (system started back on 5.3 so primary HDD was not touched) and so far I have not seen any issues. Ljubomir ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] ext4 in CentOS 5.6?
I'm sure many are running ext4 FS's in production, but just want to be re-assured that there are not currently any major issues before starting a new project that looks like it will be using ext4. I've previously been using xfs but the software for this project requires ext3/ext4. I'm always very cautious before jumping onto a new FS, (new in the sense it is officially supported now) Thanks in advance! ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[CentOS] CentOS-announce Digest, Vol 76, Issue 5
Send CentOS-announce mailing list submissions to
centos-annou...@centos.org
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.centos.org/mailman/listinfo/centos-announce
or, via email, send a message with subject or body 'help' to
centos-announce-requ...@centos.org
You can reach the person managing the list at
centos-announce-ow...@centos.org
When replying, please edit your Subject line so it is more specific
than "Re: Contents of CentOS-announce digest..."
Today's Topics:
1. CESA-2011:0885 Critical CentOS 5 i386 firefox Update
(Karanbir Singh)
2. CESA-2011:0885 Critical CentOS 5 x86_64 firefox Update
(Karanbir Singh)
3. CESA-2011:0887 Critical CentOS 5 i386 thunderbird Update
(Karanbir Singh)
4. CESA-2011:0887 Critical CentOS 5 x86_64 thunderbird Update
(Karanbir Singh)
--
Message: 1
Date: Wed, 22 Jun 2011 23:42:39 +
From: Karanbir Singh
Subject: [CentOS-announce] CESA-2011:0885 Critical CentOS 5 i386
firefox Update
To: centos-annou...@centos.org
Message-ID: <20110622234239.ga25...@chakra.karan.org>
Content-Type: text/plain; charset=us-ascii
CentOS Errata and Security Advisory 2011:0885 Critical
Upstream details at : https://rhn.redhat.com/errata/RHSA-2011-0885.html
The following updated files have been uploaded and are currently
syncing to the mirrors: ( md5sum Filename )
i386:
ad9b56940b4288c3d9dfd0257f5a3dac firefox-3.6.18-1.el5.centos.i386.rpm
b0cf54789beb9bfd8170200a4e516e59 xulrunner-1.9.2.18-2.el5_6.i386.rpm
70854a93a871dc3395715ab175050c8c xulrunner-devel-1.9.2.18-2.el5_6.i386.rpm
Source:
30a953fdffb16d1461326c4e9529d8cd firefox-3.6.18-1.el5.centos.src.rpm
37e522c26a5a1bf7ca174d7b0bfc5d47 xulrunner-1.9.2.18-2.el5_6.src.rpm
--
Karanbir Singh
CentOS Project { http://www.centos.org/ }
irc: z00dax, #cen...@irc.freenode.net
--
Message: 2
Date: Wed, 22 Jun 2011 23:42:40 +
From: Karanbir Singh
Subject: [CentOS-announce] CESA-2011:0885 Critical CentOS 5 x86_64
firefox Update
To: centos-annou...@centos.org
Message-ID: <20110622234240.ga25...@chakra.karan.org>
Content-Type: text/plain; charset=us-ascii
CentOS Errata and Security Advisory 2011:0885 Critical
Upstream details at : https://rhn.redhat.com/errata/RHSA-2011-0885.html
The following updated files have been uploaded and are currently
syncing to the mirrors: ( md5sum Filename )
x86_64:
f5376e8ff235069ed23d28580f75bad0 firefox-3.6.18-1.el5.centos.i386.rpm
eacf5c7510baa9ba57def0cb65518c23 firefox-3.6.18-1.el5.centos.x86_64.rpm
d997ba15827fe541851af08c61128d77 xulrunner-1.9.2.18-2.el5_6.i386.rpm
d4fb41dcf248c781a4d8ff0c7744c578 xulrunner-1.9.2.18-2.el5_6.x86_64.rpm
32d153ef383452b50ca07f0dd39627d8 xulrunner-devel-1.9.2.18-2.el5_6.i386.rpm
24360facb6006d6dbf47f8a4221b2915 xulrunner-devel-1.9.2.18-2.el5_6.x86_64.rpm
Source:
30a953fdffb16d1461326c4e9529d8cd firefox-3.6.18-1.el5.centos.src.rpm
37e522c26a5a1bf7ca174d7b0bfc5d47 xulrunner-1.9.2.18-2.el5_6.src.rpm
--
Karanbir Singh
CentOS Project { http://www.centos.org/ }
irc: z00dax, #cen...@irc.freenode.net
--
Message: 3
Date: Wed, 22 Jun 2011 23:49:49 +
From: Karanbir Singh
Subject: [CentOS-announce] CESA-2011:0887 Critical CentOS 5 i386
thunderbird Update
To: centos-annou...@centos.org
Message-ID: <20110622234949.ga25...@chakra.karan.org>
Content-Type: text/plain; charset=us-ascii
CentOS Errata and Security Advisory 2011:0887 Critical
Upstream details at : https://rhn.redhat.com/errata/RHSA-2011-0887.html
The following updated files have been uploaded and are currently
syncing to the mirrors: ( md5sum Filename )
i386:
092ecd00becfd2155a8d42f99b19f9a0 thunderbird-2.0.0.24-18.el5.centos.i386.rpm
Source:
bf2c5caa5c02b16210d259c8ba03144a thunderbird-2.0.0.24-18.el5.centos.src.rpm
--
Karanbir Singh
CentOS Project { http://www.centos.org/ }
irc: z00dax, #cen...@irc.freenode.net
--
Message: 4
Date: Wed, 22 Jun 2011 23:49:49 +
From: Karanbir Singh
Subject: [CentOS-announce] CESA-2011:0887 Critical CentOS 5 x86_64
thunderbird Update
To: centos-annou...@centos.org
Message-ID: <20110622234949.ga25...@chakra.karan.org>
Content-Type: text/plain; charset=us-ascii
CentOS Errata and Security Advisory 2011:0887 Critical
Upstream details at : https://rhn.redhat.com/errata/RHSA-2011-0887.html
The following updated files have been uploaded and are currently
syncing to the mirrors: ( md5sum Filename )
x86_64:
b846bdb7c086d9ac402bd6de4a0652df thunderbird-2.0.0.24-18.el5.centos.x86_64.rpm
Source:
bf2c5caa5c02b16210d259c8ba03144a thunderbird-2.0.0.24-18.el5.centos.src.rpm
--
Karanbir Singh
CentOS Project { http://www.centos.org/ }
irc: z00dax, #cen...@irc.freenode.net
--
___
C
Re: [CentOS] OT: DHCP address pool for specific MAC manufacturer
did something similar recently...
dhcpd.conf
--
class "VMware" { match if ( substring(hardware,1,3) = 00:50:56 ); }
subnet 10.1.1.224 netmask 255.255.255.240 {
#other subnet specific stuff here
pool { allow members of "VMware"; range 10.1.1.229 10.1.1.230; }
pool { deny members of "VMware"; range 10.1.1.236 10.1.1.237; }
}
--
On 06/22/11 21:44, Raymond Lillard wrote:
> Dear CentOS,
>
> This is somewhat off-topic, but I do hope to implement this on
> a CentOS system, so here goes...
>
> I would like to be able to setup a dhcpd (or like) daemon to
> maintain two IP address pools. One for devices whose leading
> three octets of the client MAC address are specified and the
> other for all other clients. Both pools would be a defined
> range on a commmon /24 subnet. There a several static IP
> devices also on this net (servers, printer, etc...). At no
> time would there be more than a dozen of the specified MAC
> range devices active.
>
> I considered splitting the /24 block into two /25 blocks and
> creating a shared-network with two subnets, but that still
> leaves no way to wild-card the lower 3 octets, which I cannot
> know in advance.
>
> In addition to DHCP, I've looked at DNSmasq and a few others
> but no joy. I don't see a solution that doesn't require a
> significant development effort.
>
> I'm off to think about possible doing this in perl. I still
> hope someone has already done this.
--
Steven Tardy
Systems Analyst
Information Technology Infrastructure
Information Technology Services
Mississippi State University
s...@its.msstate.edu
___
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CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Year in log files
Denniston, Todd A CIV NAVSURFWARCENDIV Crane wrote: >> -Original Message- >> From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On >> Behalf Of Fajar Priyanto >> Sent: Wednesday, June 22, 2011 22:23 >> To: CentOS mailing list >> Subject: Re: [CentOS] Year in log files >> >> On Thu, Jun 23, 2011 at 10:18 AM, lists-centos >> wrote: >>> You should set that log to rotate annually. That should address your >>> issue, in addition to keeping logwatch from picking up year-old >>> entries. >> >> Yes it's rotated annually. >> That's why I can argue based on common sense, by comparing the CESA >> date and the occurance in the log file. >> But if there is year, I don't have to argue at all with the auditor. > > Two suggestions, > 1) look for 'yum: Updated:' in the messages log, which should be rotated > a bit more often (and the auditor was probably fine with the time stamps > there), and if syslog is being directed to a log collector the log > collector may have different settings. > > 2) look at `rpm -qa --last` for at least the currently installed > versions, it does include the full year stamp. > If needed the auditor could link timestamps from the rpm database to > the yum log. you could also use logrpminstalls (available in rpmforge), which logs in /var/log/rpminstalls every rpm that gets installed with a timestamp that includes the year. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Year in log files
> -Original Message- > From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On > Behalf Of Fajar Priyanto > Sent: Wednesday, June 22, 2011 22:23 > To: CentOS mailing list > Subject: Re: [CentOS] Year in log files > > On Thu, Jun 23, 2011 at 10:18 AM, lists-centos > wrote: > > You should set that log to rotate annually. That should address your > > issue, in addition to keeping logwatch from picking up year-old > > entries. > > Yes it's rotated annually. > That's why I can argue based on common sense, by comparing the CESA > date and the occurance in the log file. > But if there is year, I don't have to argue at all with the auditor. Two suggestions, 1) look for 'yum: Updated:' in the messages log, which should be rotated a bit more often (and the auditor was probably fine with the time stamps there), and if syslog is being directed to a log collector the log collector may have different settings. 2) look at `rpm -qa --last` for at least the currently installed versions, it does include the full year stamp. If needed the auditor could link timestamps from the rpm database to the yum log. ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Thu, 23 Jun 2011, Giles Coochey wrote: > Well, if you have access to the source, you can probably modify some > constants to disable particular protocols, or there may be compile time > options already - it would be nice to disable automatically on runtime if > the host does not have a IPv6 protocol stack. > > The system calls in question are: > > getaddrinfo(3) > http://www.kernel.org/doc/man-pages/online/pages/man3/getaddrinfo.3.html > > or in older software: > > gethostbyname(3) > http://www.kernel.org/doc/man-pages/online/pages/man3/gethostbyname.3.html My understanding was that AI_ADDRCONFIG does exactly that, only doing a given lookup if IPv6 is configured. If that's the case, then it's just woefully underused. jh ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Thu, June 23, 2011 12:07, John Hodrien wrote: > On Thu, 23 Jun 2011, Giles Coochey wrote: > >> Yes, I'm sure it will depend on the implementation, the trailing dot was >> somewhat an educated guess from previous ISC BIND & dig tool use. :-) >> As for both the A and record, I think you will have that until IPv4 >> is fully deprecated by IPv6 and no longer exists, unless, of course, you >> want to use non IPv6 aware software (or non-IPv4 aware software... >> shudder >> - it will happen!). > > I think software still could make a better stab at things now. You're > doing > lookups on a system without any IPv6 interfaces. It's not like it's > useful information to have if it succeeds... > Well, if you have access to the source, you can probably modify some constants to disable particular protocols, or there may be compile time options already - it would be nice to disable automatically on runtime if the host does not have a IPv6 protocol stack. The system calls in question are: getaddrinfo(3) http://www.kernel.org/doc/man-pages/online/pages/man3/getaddrinfo.3.html or in older software: gethostbyname(3) http://www.kernel.org/doc/man-pages/online/pages/man3/gethostbyname.3.html ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Thu, 23 Jun 2011, Giles Coochey wrote: > Yes, I'm sure it will depend on the implementation, the trailing dot was > somewhat an educated guess from previous ISC BIND & dig tool use. :-) > As for both the A and record, I think you will have that until IPv4 > is fully deprecated by IPv6 and no longer exists, unless, of course, you > want to use non IPv6 aware software (or non-IPv4 aware software... shudder > - it will happen!). I think software still could make a better stab at things now. You're doing lookups on a system without any IPv6 interfaces. It's not like it's useful information to have if it succeeds... jh ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Thu, June 23, 2011 11:53, John Hodrien wrote: > On Thu, 23 Jun 2011, Giles Coochey wrote: > >> Can you avoid the bar.baz.domain.com.domain.com by searching for >> >> bar.baz.domain.com. >> >> (note trailing dot) >> >> ?? > > Hmm, good suggestion, that I'd not considered, Thanks. It does appear to > clear that up (down to two lookups from three: an and an A). It > doesn't > always appear to work though: > > http://bar.baz.domain.com./index.html > > This doesn't appear to universally work, but I'm not sure whether that's a > bug > with the affected web servers or not. > Yes, I'm sure it will depend on the implementation, the trailing dot was somewhat an educated guess from previous ISC BIND & dig tool use. :-) As for both the A and record, I think you will have that until IPv4 is fully deprecated by IPv6 and no longer exists, unless, of course, you want to use non IPv6 aware software (or non-IPv4 aware software... shudder - it will happen!). ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Thu, 23 Jun 2011, Giles Coochey wrote: > Can you avoid the bar.baz.domain.com.domain.com by searching for > > bar.baz.domain.com. > > (note trailing dot) > > ?? Hmm, good suggestion, that I'd not considered, Thanks. It does appear to clear that up (down to two lookups from three: an and an A). It doesn't always appear to work though: http://bar.baz.domain.com./index.html This doesn't appear to universally work, but I'm not sure whether that's a bug with the affected web servers or not. jh ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
Can you avoid the bar.baz.domain.com.domain.com by searching for bar.baz.domain.com. (note trailing dot) ?? On Thu, June 23, 2011 11:06, John Hodrien wrote: > On Wed, 22 Jun 2011, Ljubomir Ljubojevic wrote: > >> As Les wrote in another branch of the thread, search clause is if you >> try name without a domain. > > I think it's slightly more subtle and possibly more annoying than that. > > Say you have a machine called foo.mydomain.com > > By default (if you don't specify it), search is set to be mydomain.com. > > So a lookup for bar would initially be done as bar.domain.com. > > A lookup for bar.baz would initially be searched for as bar.baz (because > it > has at least ndots in it), but if that failed, would then be looked up as > bar.baz.domain.com. > > Equally a search for baz.domain.com (where baz didn't exist) would be > looked > up first as baz.domain.com and then as baz.domain.com.domain.com. > > This appears to be doubly annoying with programs compile with IPv6 support > where there aren't records. > > So a typical valid lookup for machine.domain.com becomes: > > lookup for machine.domain.com (not found) > lookup for machine.domain.com.domain.com (not found) > A lookup for machine.domain.com (found) > > jh > ___ > CentOS mailing list > CentOS@centos.org > http://lists.centos.org/mailman/listinfo/centos > ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] inconsistent DNS results - ping vs dig vs nslookup
On Wed, 22 Jun 2011, Ljubomir Ljubojevic wrote: > As Les wrote in another branch of the thread, search clause is if you > try name without a domain. I think it's slightly more subtle and possibly more annoying than that. Say you have a machine called foo.mydomain.com By default (if you don't specify it), search is set to be mydomain.com. So a lookup for bar would initially be done as bar.domain.com. A lookup for bar.baz would initially be searched for as bar.baz (because it has at least ndots in it), but if that failed, would then be looked up as bar.baz.domain.com. Equally a search for baz.domain.com (where baz didn't exist) would be looked up first as baz.domain.com and then as baz.domain.com.domain.com. This appears to be doubly annoying with programs compile with IPv6 support where there aren't records. So a typical valid lookup for machine.domain.com becomes: lookup for machine.domain.com (not found) lookup for machine.domain.com.domain.com (not found) A lookup for machine.domain.com (found) jh ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Chicken and egg question: passwd and cronjob
On Thu, Jun 23, 2011 at 3:44 PM, Michael Gliwinski wrote: > On Thursday 23 Jun 2011 07:46:01 Fajar Priyanto wrote: >> I understand that cronjob for root will fail when the password expires. > > AFAIK, account does not need to have a password at all for cron to work. > > Apart from that if you're going to automatically reset root's password you may > as well just avoid expiring it at all. In /var/log/cron I see this when the password expires. And cronjob fail to run. Jun 23 02:50:01 my-srv crond[4424]: CRON (root) ERROR: failed to open PAM security session: Success Jun 23 02:50:01 my-srv crond[4424]: CRON (root) ERROR: cannot set security context Jun 23 03:00:01 my-srv crond[4425]: Authentication token is no longer valid; new one required ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] Chicken and egg question: passwd and cronjob
On Thursday 23 Jun 2011 07:46:01 Fajar Priyanto wrote: > I understand that cronjob for root will fail when the password expires. AFAIK, account does not need to have a password at all for cron to work. Apart from that if you're going to automatically reset root's password you may as well just avoid expiring it at all. -- Michael Gliwinski Henderson Group Information Services 9-11 Hightown Avenue, Newtownabby, BT36 4RT Phone: 028 9034 3319 ** The information in this email is confidential and may be legally privileged. It is intended solely for the addressee and access to the email by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients, any opinions or advice contained in this e-mail are subject to the terms and conditions expressed in the governing client engagement leter or contract. If you have received this email in error please notify supp...@henderson-group.com John Henderson (Holdings) Ltd Registered office: 9 Hightown Avenue, Mallusk, County Antrim, Northern Ireland, BT36 4RT. Registered in Northern Ireland Registration Number NI010588 Vat No.: 814 6399 12 * ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
