Re: software or hardware raid?
Tim: >> I have a UPS sitting next to me, right now, in pieces, which (half) >> died in a most peculiar manner: >> >> A burning smell was eventually traced to it. There's no visible >> signs of burning, and no schematic available for the model, that I >> can find. A rather acrid smell, not one I'm used to with component >> failure, I'm beginning to suspect a large AC transformer. Mauricio Tavares: > Did you check the impedance of the transformer? Not yet, the lack of schematics put me off, I'd really have to delve into reverse-engineering it to fix it (assuming I could get any needed parts), it's a very old model (SOLA 310). If the transformer had cooked one of its windings, I doubt I'd find replacement (there are multiple windings), and the board is chock full of ICs (very few discrete components). I never really bothered with UPSs at home before, but we've been getting lots of little power cuts the last year. Previously things were very good here. You might have gone a year or more without any interruptions. The other thing is that this only has a few minutes of supply capability, allowing you to ride through blips on the mains, and cleanly shutdown during longer power failures, but not carry on working for a prolonged period. Though my modern low-power PC gives much more runtime than the UPS's prediction in its manual. And it was quite noisy in stand-by mode, while AC powered, it had quite a hum to it. Bad enough that I'd run it in the adjacent room, with long leads running to and from it. Much as I dislike waste, and I repair a lot of equipment, I've been considering something newer with more capacity. -- NB: All unexpected mail to my mailbox is automatically deleted. I will only get to see the messages that are posted to the list. The following system info data is generated fresh for each post: uname -rsvp Linux 6.1.14-100.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Feb 26 00:31:11 UTC 2023 x86_64 ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Thu, Mar 2, 2023 at 10:42 PM Tim via users wrote: > > On Thu, 2023-03-02 at 17:09 -0600, Chris Adams wrote: > > Lots of the time, UPSes and generators are not actively monitored and > > tested. An untested backup system is not a backup system, it's just > > another point of failure! I have seen failures of big UPSes, > > generators, transfer switches... you name it, even if it is "redundant", > > it can (and will) still fail. > > I have a UPS sitting next to me, right now, in pieces, which (half) > died in a most peculiar manner: > > A burning smell was eventually traced to it. There's no visible signs > of burning, and no schematic available for the model, that I can find. > A rather acrid smell, not one I'm used to with component failure, I'm > beginning to suspect a large AC transformer. > Did you check the impedance of the transformer? > While running off the mains its output is a (too) low voltage, but > still high enough for most switch-mode power supplies to run normally > (i.e. the computer and monitor). It has some kind of AC voltage > regulation built into it to deal with under and over-voltage. The > AC supply was normal, at the time. > > But running off its battery it produces the full 240 volts it's > supposed to. > > -- > > uname -rsvp > Linux 3.10.0-1160.83.1.el7.x86_64 #1 SMP Wed Jan 25 16:41:43 UTC 2023 x86_64 > > Boilerplate: All unexpected mail to my mailbox is automatically deleted. > I will only get to see the messages that are posted to the mailing list. > > ___ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Thu, 2023-03-02 at 17:09 -0600, Chris Adams wrote: > Lots of the time, UPSes and generators are not actively monitored and > tested. An untested backup system is not a backup system, it's just > another point of failure! I have seen failures of big UPSes, > generators, transfer switches... you name it, even if it is "redundant", > it can (and will) still fail. I have a UPS sitting next to me, right now, in pieces, which (half) died in a most peculiar manner: A burning smell was eventually traced to it. There's no visible signs of burning, and no schematic available for the model, that I can find. A rather acrid smell, not one I'm used to with component failure, I'm beginning to suspect a large AC transformer. While running off the mains its output is a (too) low voltage, but still high enough for most switch-mode power supplies to run normally (i.e. the computer and monitor). It has some kind of AC voltage regulation built into it to deal with under and over-voltage. The AC supply was normal, at the time. But running off its battery it produces the full 240 volts it's supposed to. -- uname -rsvp Linux 3.10.0-1160.83.1.el7.x86_64 #1 SMP Wed Jan 25 16:41:43 UTC 2023 x86_64 Boilerplate: All unexpected mail to my mailbox is automatically deleted. I will only get to see the messages that are posted to the mailing list. ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Wed, Mar 1, 2023 at 3:02 PM Ranjan Maitra wrote: > > I would like to RAID two of my disks, and I was wondering if the > recommendation is to do software or hardware RAID? Also see "A Journal for MD/RAID5", https://lwn.net/Articles/665299/ and "ext3 and RAID: silent data killers?", https://lwn.net/Articles/349970/ . But both articles are kind of old. Jeff ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
Once upon a time, George N. White III said: > Some data can be replaced, but there are also real-time data flows > where data are lost forever when the system does down. I recall a > lost-of-data incident where the system was on UPS+ generator but > IT hadn't received the replacement for a failed UPS battery in the > network closet. Lots of the time, UPSes and generators are not actively monitored and tested. An untested backup system is not a backup system, it's just another point of failure! I have seen failures of big UPSes, generators, transfer switches... you name it, even if it is "redundant", it can (and will) still fail. -- Chris Adams ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Thu, Mar 2, 2023 at 4:49 PM Roger Heflin wrote: > if you suddenly lose power there is a fair chance that the last few > blocks of data had not made it to disk yet. > Some data can be replaced, but there are also real-time data flows where data are lost forever when the system does down. I recall a lost-of-data incident where the system was on UPS+ generator but IT hadn't received the replacement for a failed UPS battery in the network closet. -- George N. White III ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Thu, Mar 2, 2023 at 4:43 PM Richard Shaw wrote: > On Thu, Mar 2, 2023 at 2:25 PM Ranjan Maitra wrote: > >> Thanks to everybody. I recall discussion from several years ago on the >> benefits of software over hardware RAID. I had completely forgotten about >> UPS for this new machine. Btw, what happens if power goes out (and I do not >> have UPS)? >> > > If you don't have a UPS, I would recommend BTRFS mostly because it's a > Copy-On-Write (COW) filesystem. EXT4 journaling only protects the > filesystem, not the files themselves. BRTFS does a checksum of the files as > well, and because it writes out a new file, if that's interrupted, you > still at least have the previous version of the file. > > Depending on the type of files, you may also want to take advantage of > transparent compression. I know BTRFS took a long time to stabilize but it > works pretty well for stand alone and RAID 1. I'm not sure if I would trust > it for RAID 5 just yet. > Here in Canada, we often get short power hits, often from a vehicle sliding on snow or ice into a power pole. That often causes widespread loss-of-power just long enough to stop computers. UPS means jobs keep going instead waiting for reboot and filesystem repairs, followed by restarting jobs that otherwise would be finished. Sometimes systems don't come up without added work. -- George N. White III ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: Fedora 37 installer only sees 1 of 3 4TB drives on NVMe card
On Thu, Mar 2, 2023 at 3:50 PM Ranjan Maitra wrote: > > Hello, > > I have 3 NVMe PCIe M.2 SSD part number CT4000P3PSSD8 on my card. However, the > Fedora installer only sees one of these three SSDs. I tried looking at them > using nvme list and only see one (and two separate 256 GB SSDs). I looked > into the case, and all three 4 TB drives are there, with lights blinking. I > am sorry not to give more relevant info right now (I do not know what to > give), but the machine shipped by Dell (the 4 TB drives were purchased > separately) is Precision 7920 Tower XCTO Base (it came with the 2 256 GB > SSDs). > For starters, check backplane wiring. Then, consider moving drives around to see if the problem follows the drive(s). > Many thanks, and best wishes, > Ranjan > ___ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
Once upon a time, Ranjan Maitra said: > Thanks, this will be a fairly high uptime machine (not allowed to call it a > server here, because that is central IT's role to have and administer:-), > running lots of jobs at least a large part of the time, but the RAID will be > on the /. It is more to keep the machine going if one of the two / drives > fail (and till such time as I can get and put in a new one). That's a good target for RAID (I just like to remind people RAID is not backups, because double drive failures happen, filesystem corruption happens, somebody deletes the wrong file happens, and so on). > I see, so your recommendation is to go for xfs? It's what I use, in part because I also run RHEL and CentOS servers, where XFS is the default and preferred filesystem by Red Hat for a while now. I think the pros and cons of XFS vs ext4 probably aren't that significant in most use. XFS doesn't currently support any kind of shrink operation (more of an issue if you are using LVM but not LVM thin pools, and there is some work on adding this). ext4 can also journal data (doesn't by default by can be enabled), which gives additional protection (at an additional performance cost). XFS is higher performance for some uses, but that probably gets into specifics about your use cases to know if it really is (or if it matters). XFS supports reflinks while ext4 does not, which again can be useful for certain things. If you are familiar and happy with ext4 though, there's no reason to switch unless you see something in particular that XFS would do better in your use. ext4 is not going away any time soon, and both ext4 and XFS are mature and stable filesystems (and both are still getting development). -- Chris Adams ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
Thanks, Chris! On Thu Mar02'23 02:49:49PM, Chris Adams wrote: > From: Chris Adams > Date: Thu, 2 Mar 2023 14:49:49 -0600 > To: users@lists.fedoraproject.org > Reply-To: Community support for Fedora users > Subject: Re: software or hardware raid? > > Once upon a time, Ranjan Maitra said: > > Thanks to everybody. I recall discussion from several years ago on the > > benefits of software over hardware RAID. I had completely forgotten about > > UPS for this new machine. Btw, what happens if power goes out (and I do not > > have UPS)? > > Linux software RAID keeps a bitmap of pending writes by default, which > is an okay (but not perfect) mechanism to recover from unexpected > shutdown. There's also an option to keep a write journal instead, but > unless you put that on a separate fast device (e.g. quality SSD with > long write lifetime), it'll impact performance significantly. > > There are trade-offs between various types of SW and HW RAID, so really > the first question would be "what are your requirements and > expectations". Are you talking about a high-uptime server, or a desktop > where you just want to make hardware failure less annoying? RAID (HW or > SW) is NOT backups, so you shouldn't depend on it for saving your > data. Thanks, this will be a fairly high uptime machine (not allowed to call it a server here, because that is central IT's role to have and administer:-), running lots of jobs at least a large part of the time, but the RAID will be on the /. It is more to keep the machine going if one of the two / drives fail (and till such time as I can get and put in a new one). For /home (which is where my data reside), I have 2 backups done using rsync every hour. I plan to copy the actual /home to the second one, and I was thinking that the third one would be incremental backup (kept for a year, since I occasionally realize weeks and months later that I really want a file back from long ago) or so. > > HW RAID has some advantages - quality controllers will have > battery-backed cache, so things like write journaling don't impact > performance and recovery from unexpected power failures is basically > instantaneous. For high performance requirements, there's less overhead > with HW RAID (because data only has to transit the bus once, then the > RAID controller has its own paths to the drives). But HW RAID typically > requires odd and/or proprietary software to manage, detect failures, > etc. Depending on the RAID level you are using, recovery from a failure > of the controller itself can be harder too. > > > Btw, I still stick to ext4, largely because of inertia (and because I have > > used lvm in the past and hated its naming conventions, I think, but there > > were also other limitations that I do not now recall) and have stayed away > > from zfs or btrfs or lvm. I am not sure what to do now. Clearly, things > > have moved far on. > > I'm generally in the XFS on LVM (on SW mdraid when needed) camp > myself... LVM adds a significant layer of flexibility and ability, but > still using more "traditional" filesystems like XFS and ext4. I had > poor experiences with ZFS at a former job, and am still a little leery > of some of the approach BTRFS takes. > > I'm playing with adding the dm-integrity layer for my SW mdraid (so then > XFS on LVM on mdraid on integrity on drive) setup as an additional check > against silent drive failures, but again, unless you put that data on a > separate fast SSD, it slows down performance a lot. I see, so your recommendation is to go for xfs? Many thanks again, and best wishes, Ranjan ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Fedora 37 installer only sees 1 of 3 4TB drives on NVMe card
Hello, I have 3 NVMe PCIe M.2 SSD part number CT4000P3PSSD8 on my card. However, the Fedora installer only sees one of these three SSDs. I tried looking at them using nvme list and only see one (and two separate 256 GB SSDs). I looked into the case, and all three 4 TB drives are there, with lights blinking. I am sorry not to give more relevant info right now (I do not know what to give), but the machine shipped by Dell (the 4 TB drives were purchased separately) is Precision 7920 Tower XCTO Base (it came with the 2 256 GB SSDs). Many thanks, and best wishes, Ranjan ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
Once upon a time, Ranjan Maitra said: > Thanks to everybody. I recall discussion from several years ago on the > benefits of software over hardware RAID. I had completely forgotten about UPS > for this new machine. Btw, what happens if power goes out (and I do not have > UPS)? Linux software RAID keeps a bitmap of pending writes by default, which is an okay (but not perfect) mechanism to recover from unexpected shutdown. There's also an option to keep a write journal instead, but unless you put that on a separate fast device (e.g. quality SSD with long write lifetime), it'll impact performance significantly. There are trade-offs between various types of SW and HW RAID, so really the first question would be "what are your requirements and expectations". Are you talking about a high-uptime server, or a desktop where you just want to make hardware failure less annoying? RAID (HW or SW) is NOT backups, so you shouldn't depend on it for saving your data. HW RAID has some advantages - quality controllers will have battery-backed cache, so things like write journaling don't impact performance and recovery from unexpected power failures is basically instantaneous. For high performance requirements, there's less overhead with HW RAID (because data only has to transit the bus once, then the RAID controller has its own paths to the drives). But HW RAID typically requires odd and/or proprietary software to manage, detect failures, etc. Depending on the RAID level you are using, recovery from a failure of the controller itself can be harder too. > Btw, I still stick to ext4, largely because of inertia (and because I have > used lvm in the past and hated its naming conventions, I think, but there > were also other limitations that I do not now recall) and have stayed away > from zfs or btrfs or lvm. I am not sure what to do now. Clearly, things have > moved far on. I'm generally in the XFS on LVM (on SW mdraid when needed) camp myself... LVM adds a significant layer of flexibility and ability, but still using more "traditional" filesystems like XFS and ext4. I had poor experiences with ZFS at a former job, and am still a little leery of some of the approach BTRFS takes. I'm playing with adding the dm-integrity layer for my SW mdraid (so then XFS on LVM on mdraid on integrity on drive) setup as an additional check against silent drive failures, but again, unless you put that data on a separate fast SSD, it slows down performance a lot. -- Chris Adams ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
if you suddenly lose power there is a fair chance that the last few blocks of data had not made it to disk yet. For the most part this only only a big issue with oracle db and/or mysql and/or stuff with critical transactions that cannot be lost and that need a consistent state when they come back up and flush writes and/or use direct io. For anything else the bit of data you lost is not so much an issue since whatever that was stopped working and did not finish. I run cameras and other stuff, and the 5-30 seconds I could lose because of this is minor compared to what I lost for being down for however long I was down for. On Thu, Mar 2, 2023 at 2:25 PM Ranjan Maitra wrote: > > Thanks to everybody. I recall discussion from several years ago on the > benefits of software over hardware RAID. I had completely forgotten about UPS > for this new machine. Btw, what happens if power goes out (and I do not have > UPS)? > > Btw, I still stick to ext4, largely because of inertia (and because I have > used lvm in the past and hated its naming conventions, I think, but there > were also other limitations that I do not now recall) and have stayed away > from zfs or btrfs or lvm. I am not sure what to do now. Clearly, things have > moved far on. > > Thanks, > Ranjan > > On Thu Mar02'23 02:19:25PM, George N. White III wrote: > > From: "George N. White III" > > Date: Thu, 2 Mar 2023 14:19:25 -0400 > > To: Community support for Fedora users > > Reply-To: Community support for Fedora users > > Subject: Re: software or hardware raid? > > > > On Wed, Mar 1, 2023 at 4:02 PM Ranjan Maitra wrote: > > > > > Hi, > > > > > > I would like to RAID two of my disks, and I was wondering if the > > > recommendation is to do software or hardware RAID? > > > > > > > Software RAID works very well on modern hardware. You do want to make sure > > a power > > outage can't cause a shutdown before the RAID is safely dismounted. > > Ideally a your site > > has a reliable generator and your server has a UPS that can hold power > > while waiting for > > the generator to come online and also long enough to ensure a clean > > shutdown when the > > generator fails. > > > > -- > > George N. White III > > > ___ > > users mailing list -- users@lists.fedoraproject.org > > To unsubscribe send an email to users-le...@lists.fedoraproject.org > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > > Do not reply to spam, report it: > > https://pagure.io/fedora-infrastructure/new_issue > ___ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Thu, Mar 2, 2023 at 2:25 PM Ranjan Maitra wrote: > Thanks to everybody. I recall discussion from several years ago on the > benefits of software over hardware RAID. I had completely forgotten about > UPS for this new machine. Btw, what happens if power goes out (and I do not > have UPS)? > If you don't have a UPS, I would recommend BTRFS mostly because it's a Copy-On-Write (COW) filesystem. EXT4 journaling only protects the filesystem, not the files themselves. BRTFS does a checksum of the files as well, and because it writes out a new file, if that's interrupted, you still at least have the previous version of the file. Depending on the type of files, you may also want to take advantage of transparent compression. I know BTRFS took a long time to stabilize but it works pretty well for stand alone and RAID 1. I'm not sure if I would trust it for RAID 5 just yet. Thanks, Richard ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
Thanks to everybody. I recall discussion from several years ago on the benefits of software over hardware RAID. I had completely forgotten about UPS for this new machine. Btw, what happens if power goes out (and I do not have UPS)? Btw, I still stick to ext4, largely because of inertia (and because I have used lvm in the past and hated its naming conventions, I think, but there were also other limitations that I do not now recall) and have stayed away from zfs or btrfs or lvm. I am not sure what to do now. Clearly, things have moved far on. Thanks, Ranjan On Thu Mar02'23 02:19:25PM, George N. White III wrote: > From: "George N. White III" > Date: Thu, 2 Mar 2023 14:19:25 -0400 > To: Community support for Fedora users > Reply-To: Community support for Fedora users > Subject: Re: software or hardware raid? > > On Wed, Mar 1, 2023 at 4:02 PM Ranjan Maitra wrote: > > > Hi, > > > > I would like to RAID two of my disks, and I was wondering if the > > recommendation is to do software or hardware RAID? > > > > Software RAID works very well on modern hardware. You do want to make sure > a power > outage can't cause a shutdown before the RAID is safely dismounted. > Ideally a your site > has a reliable generator and your server has a UPS that can hold power > while waiting for > the generator to come online and also long enough to ensure a clean > shutdown when the > generator fails. > > -- > George N. White III > ___ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On Wed, Mar 1, 2023 at 4:02 PM Ranjan Maitra wrote: > Hi, > > I would like to RAID two of my disks, and I was wondering if the > recommendation is to do software or hardware RAID? > Software RAID works very well on modern hardware. You do want to make sure a power outage can't cause a shutdown before the RAID is safely dismounted. Ideally a your site has a reliable generator and your server has a UPS that can hold power while waiting for the generator to come online and also long enough to ensure a clean shutdown when the generator fails. -- George N. White III ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On 2023-03-01 12:01 pm, Ranjan Maitra wrote: Hi, I would like to RAID two of my disks, and I was wondering if the recommendation is to do software or hardware RAID? Thanks, Ranjan ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue Hi; I've a btrfs RAID1 array comprised of two 2tb hard drives up and running for just under a year. It's mounted as /home and backed up regularly to a external usb hard drive. I've thought of upgrading to ssd drives in the PCI slots though. Joe ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: open files limit was: Re: Enabling Apache HTTP/2 => Too many open files error
On Mar 2, 2023, at 03:35, Roberto Ragusa wrote: > > On 2/27/23 13:44, Richard W.M. Jones wrote: > >> It turns out that the default open file limit (1024!) is too low. To >> change this and fix the problem: >> # systemctl edit httpd > This low limit can be an issue for many processes. > I don't understand why it is still so low in modern machines. > I've raised it a lot, many years ago, by editing > /etc/security/limits.conf, but I now see I get again > 1024. My guess is systemd is deciding by itself, and not > respecting my settings. /etc /security/limits.conf is only read by pam_limits.so in the PAM stack. Systemd processes don’t automatically use pam (although if you use ‘su’ or login somehow). You’d change it with the LimitsNOfile systemd directive. I think there’s a default setting in /etc/systemd/system.conf you can override the default. (Double-check man systemd.resource-control) -- Jonathan Billings ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: open files limit was: Re: Enabling Apache HTTP/2 => Too many open files error
On Thu, Mar 2, 2023 at 2:35 AM Roberto Ragusa wrote: > > On 2/27/23 13:44, Richard W.M. Jones wrote: > > > It turns out that the default open file limit (1024!) is too low. To > > change this and fix the problem: > > > ># systemctl edit httpd > This low limit can be an issue for many processes. > I don't understand why it is still so low in modern machines. > I've raised it a lot, many years ago, by editing > /etc/security/limits.conf, but I now see I get again > 1024. My guess is systemd is deciding by itself, and not > respecting my settings. > > Regards. > Systemd is started really early and seems to use the defaults. Anything started from systemd needs to explicitly override in the startup script. Looking at the initramfs I don't see limits.conf in there so when the switchroot happens and systemd gets started it would have the default limits. ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
RE: software or hardware raid?
-Original Message- From: Ranjan Maitra Sent: Wednesday, March 1, 2023 9:02 PM To: Community Support for Fedora Users Subject: software or hardware raid? Hi, I would like to RAID two of my disks, and I was wondering if the recommendation is to do software or hardware RAID? Thanks, Ranjan ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue In most cases, i would say: soft raid - nowadays CPU's can do easily the workload, compared to 20 years ago, - no dependency on specific hardware If you had a g HP-server, with a vast amount of drives, and wanting raid-60, and having enough spare-parts, you could consider HW-raid. Dit bericht kan informatie bevatten die niet voor u is bestemd. Indien u niet de geadresseerde bent of dit bericht abusievelijk aan u is toegezonden, wordt u verzocht dat aan de afzender te melden en het bericht te verwijderen. De Staat aanvaardt geen aansprakelijkheid voor schade, van welke aard ook, die verband houdt met risico's verbonden aan het elektronisch verzenden van berichten. This message may contain information that is not intended for you. If you are not the addressee or if this message was sent to you by mistake, you are requested to inform the sender and delete the message. The State accepts no liability for damage of any kind resulting from the risks inherent in the electronic transmission of messages. ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
open files limit was: Re: Enabling Apache HTTP/2 => Too many open files error
On 2/27/23 13:44, Richard W.M. Jones wrote: It turns out that the default open file limit (1024!) is too low. To change this and fix the problem: # systemctl edit httpd This low limit can be an issue for many processes. I don't understand why it is still so low in modern machines. I've raised it a lot, many years ago, by editing /etc/security/limits.conf, but I now see I get again 1024. My guess is systemd is deciding by itself, and not respecting my settings. Regards. -- Roberto Ragusamail at robertoragusa.it ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
Re: software or hardware raid?
On 3/1/23 21:01, Ranjan Maitra wrote: Hi, I would like to RAID two of my disks, and I was wondering if the recommendation is to do software or hardware RAID? Software. Everything you need is in the mdadm command. Regards. -- Roberto Ragusamail at robertoragusa.it ___ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
