Re: R710/PERC H700/H800/MD1200 disk naming
There's some truth to that, as far as "imaging" scenarios for backups. Using 'dd' is never an issue and is always an option for imaging purposes; just not elegant or ideal. But, "new" imaging tools now understand LVM. E.g., http://partimage-ng.net/index.php?title=Main_Page In the ideal situation, the file system, software RAID, and LVM2 should all be collapsed into a single layer. It's already a bit silly that the software RAID and LVM2 are completely separate layers (that overlap a bit) in Linux. If ZFS or something like it (Btrfs?) becomes mainstream in Linux, a lot of this unnecessary complexity will be a thing of the past and your pre-historic IS degree will be from 35 yrs ago ;-P -Bond On Tue, 2010-08-03 at 11:07 -0400, J. Epperson wrote: > On Tue, August 3, 2010 09:41, Dameon Wagner wrote: > > On Tue, Aug 03, 2010 at 12:19:53PM +0100, John Hodrien scribbled in "Re: > > R710/PERC H700/H800/MD1200 disk naming": > >> LVM merely gives you options that you don't have without it. It's > >> really not a pain; treat it simply and there's really very little to > >> it. There's times I am annoyed by a lack of LVM on machines because I > >> find it handy to use what LVM can offer me, but it's too late. There > >> aren't times I find the inverse to be the case. > > > > Not an overriding argument, but I've found the inverse to be the case in > imaging scenarios. It's simple to backup/restore /dev/sdax from a > partition image, /dev/mapper/VolGroup00-LogVolxx not so much. OTOH you > can snapshot LVMs without having to unmount them. But I'm a dinosaur with > an IS degree from 30 years ago, and my mind just wraps around physical > partition scenarios better. > > ___ > Linux-PowerEdge mailing list > Linux-PowerEdge@dell.com > https://lists.us.dell.com/mailman/listinfo/linux-poweredge > Please read the FAQ at http://lists.us.dell.com/faq ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
On Tue, August 3, 2010 09:41, Dameon Wagner wrote: > On Tue, Aug 03, 2010 at 12:19:53PM +0100, John Hodrien scribbled in "Re: > R710/PERC H700/H800/MD1200 disk naming": >> LVM merely gives you options that you don't have without it. It's >> really not a pain; treat it simply and there's really very little to >> it. There's times I am annoyed by a lack of LVM on machines because I >> find it handy to use what LVM can offer me, but it's too late. There >> aren't times I find the inverse to be the case. > Not an overriding argument, but I've found the inverse to be the case in imaging scenarios. It's simple to backup/restore /dev/sdax from a partition image, /dev/mapper/VolGroup00-LogVolxx not so much. OTOH you can snapshot LVMs without having to unmount them. But I'm a dinosaur with an IS degree from 30 years ago, and my mind just wraps around physical partition scenarios better. ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
On Tue, Aug 03, 2010 at 12:19:53PM +0100, John Hodrien scribbled in "Re: R710/PERC H700/H800/MD1200 disk naming": > On Tue, 3 Aug 2010, Robin Bowes wrote: > > > On 03/08/10 11:46, Stroller wrote: > >> On 2 Aug 2010, at 22:11, Ken Nishimura wrote: > >>> I assume that making a few large virtual disks (mostly segregated > >>> by disk type and enclosure location) and using LVM to slice and dice > >>> is the way to go? > >> I find the thought horrifying. I choose servers like the PowerEdge > >> because they have hardware RAID. LVM would seem, as a wild > >> generalisation, to undermine that. > > Not at all. > > > > You still have your hardware RAID, but you can manage volumes and usage > > more easily on top if it. Much easier than using physical partitions. > > I couldn't agree more, and I think this is really important to stress. I'll second (or third?) that. > LVM merely gives you options that you don't have without it. It's really not > a pain; treat it simply and there's really very little to it. There's times I > am annoyed by a lack of LVM on machines because I find it handy to use what > LVM can offer me, but it's too late. There aren't times I find the inverse to > be the case. Ever since I found LVM all those years ago, I've loved the flexibility that it provides -- and for once, this flexibility comes without any compromise or negative side effect. I simply don't build servers without LVM anymore. And to make Stroller happy, you can still use file-system labels ;) > Combine LVM with iSCSI and you really can have some serious fun that you'd > never even think of if you're not in that mindset. Again, I heartily agree. We recently expanded our SAN using Debian, LVM, iSCSI, and a 16 hot-swap chassis. Provisioning targets is a breeze, and unscripted would take only 3 commands, 4 if you're using ACLs for the initiators. (To be fair, if you want persistence we have to edit the iSCSI daemon's config file, but that's hardly an issue). And I haven't even started on snapshot backups either... LVM is made of win. Cheers. Dameon. -- ><> ><> ><> ><> ><> ><> ooOoo <>< <>< <>< <>< <>< <>< Dr. Dameon Wagner, Senior ICT Specialist, Depts. of Computer Science & Information Systems, Rhodes University, Grahamstown, South Africa. :Beta tester for Pegasus & Mercury/32 (www.pmail.com): ><> ><> ><> ><> ><> ><> ooOoo <>< <>< <>< <>< <>< <>< ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
On Tue, 3 Aug 2010, Robin Bowes wrote: > On 03/08/10 11:46, Stroller wrote: >> On 2 Aug 2010, at 22:11, Ken Nishimura wrote: >>> I assume that making a few large virtual disks (mostly segregated >>> by disk type and enclosure location) and using LVM to slice and dice >>> is the way to go? >> I find the thought horrifying. I choose servers like the PowerEdge >> because they have hardware RAID. LVM would seem, as a wild >> generalisation, to undermine that. > Not at all. > > You still have your hardware RAID, but you can manage volumes and usage > more easily on top if it. Much easier than using physical partitions. I couldn't agree more, and I think this is really important to stress. LVM merely gives you options that you don't have without it. It's really not a pain; treat it simply and there's really very little to it. There's times I am annoyed by a lack of LVM on machines because I find it handy to use what LVM can offer me, but it's too late. There aren't times I find the inverse to be the case. Combine LVM with iSCSI and you really can have some serious fun that you'd never even think of if you're not in that mindset. jh ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
On 03/08/10 11:46, Stroller wrote: > On 2 Aug 2010, at 22:11, Ken Nishimura wrote: >> I assume that making a few large virtual disks (mostly segregated >> by disk type and enclosure location) and using LVM to slice and dice >> is the way to go? > I find the thought horrifying. I choose servers like the PowerEdge > because they have hardware RAID. LVM would seem, as a wild > generalisation, to undermine that. Not at all. You still have your hardware RAID, but you can manage volumes and usage more easily on top if it. Much easier than using physical partitions. R. -- "Feed that ego and you starve the soul" - Colonel J.D. Wilkes http://www.theshackshakers.com/ ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
On 2 Aug 2010, at 22:11, Ken Nishimura wrote: > ... I think I will go with LVM. It has some nice other properties > as well. That seems to add complexity, relative to: $ cat /etc/fstab | grep LABEL LABEL=boot /boot ext2 noauto,noatime 1 2 LABEL=/ / ext4 noatime 0 1 LABEL=swap noneswap sw 0 0 LABEL=space /mnt/space ext4 noatime 0 3 $ I believe DeadRat may allow you to use labels in GRUB, too. > I assume that making a few large virtual disks (mostly segregated > by disk type and enclosure location) and using LVM to slice and dice > is the way to go? I find the thought horrifying. I choose servers like the PowerEdge because they have hardware RAID. LVM would seem, as a wild generalisation, to undermine that. Stroller. ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
Alex and others - Thanks. I think I will go with LVM. It has some nice other properties as well. I assume that making a few large virtual disks (mostly segregated by disk type and enclosure location) and using LVM to slice and dice is the way to go? Thx, Ken --- Jefferson Cowart wrote: > The recommendations I've seen are to avoid using /dev/sdx for exactly this > reason. Instead you can use either file system labels or otherwise persistent > names generated by udev based on parameters that won't change. Another (better?) solution is to use LVM logical volumes for your filesystems - the kernel scans all relevant storage at startup and identifies LVM PVs and reads their metadata from them, so even if the underlying device names/locations change, everything still "just works." (/boot, which cannot be LVM, is another issue, but GRUB's access to that is typically mediated by the BIOS, which is at least a little less likely to renumber things the way the Linux kernel does...) @alex -- mailto:alex.du...@mac.com ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
Re: R710/PERC H700/H800/MD1200 disk naming
Jefferson Cowart wrote: > The recommendations I've seen are to avoid using /dev/sdx for exactly this > reason. Instead you can use either file system labels or otherwise persistent > names generated by udev based on parameters that won't change. Another (better?) solution is to use LVM logical volumes for your filesystems - the kernel scans all relevant storage at startup and identifies LVM PVs and reads their metadata from them, so even if the underlying device names/locations change, everything still "just works." (/boot, which cannot be LVM, is another issue, but GRUB's access to that is typically mediated by the BIOS, which is at least a little less likely to renumber things the way the Linux kernel does...) @alex -- mailto:alex.du...@mac.com ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
RE: R710/PERC H700/H800/MD1200 disk naming
Ken, Refer this link. This might help you in locking a device name to disk. http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/html/Online_St orage_Reconfiguration_Guide/persistent_naming.html -- Ashokan Vellimalai Linux Engineering Dell | Product Group, Bangalore Development Center -Original Message- From: linux-poweredge-boun...@dell.com [mailto:linux-poweredge-boun...@dell.com] On Behalf Of Jefferson Cowart Sent: Monday, August 02, 2010 10:50 PM To: linux-poweredge-Lists Subject: RE: R710/PERC H700/H800/MD1200 disk naming The recommendations I've seen are to avoid using /dev/sdx for exactly this reason. Instead you can use either file system labels or otherwise persistent names generated by udev based on parameters that won't change. -- Thank You Jefferson Cowart Network and Systems Administrator Claremont University Consortium -Original Message- From: linux-poweredge-boun...@dell.com on behalf of Ken Nishimura Sent: Mon 8/2/2010 10:12 AM To: linux-poweredge@dell.com Subject: R710/PERC H700/H800/MD1200 disk naming Have a R710 running RHEL4.8 with a internal H700 supporting two virtual drives using internal disks and a H800 supporting two virtual drives in an external MD1200 enclosure. It seems that the device name (/dev/sd?) that is assigned to each virtual drive is somewhat arbitrary. It was in order of creation, but after a reboot, it changed to order of enclosure/drive. This, as you can imangine, is not a good thing. What is the best way of locking a device name to a virtual disk? udev? Thanks! Ken ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
RE: R710/PERC H700/H800/MD1200 disk naming
The recommendations I've seen are to avoid using /dev/sdx for exactly this reason. Instead you can use either file system labels or otherwise persistent names generated by udev based on parameters that won't change. -- Thank You Jefferson Cowart Network and Systems Administrator Claremont University Consortium -Original Message- From: linux-poweredge-boun...@dell.com on behalf of Ken Nishimura Sent: Mon 8/2/2010 10:12 AM To: linux-poweredge@dell.com Subject: R710/PERC H700/H800/MD1200 disk naming Have a R710 running RHEL4.8 with a internal H700 supporting two virtual drives using internal disks and a H800 supporting two virtual drives in an external MD1200 enclosure. It seems that the device name (/dev/sd?) that is assigned to each virtual drive is somewhat arbitrary. It was in order of creation, but after a reboot, it changed to order of enclosure/drive. This, as you can imangine, is not a good thing. What is the best way of locking a device name to a virtual disk? udev? Thanks! Ken ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
R710/PERC H700/H800/MD1200 disk naming
Have a R710 running RHEL4.8 with a internal H700 supporting two virtual drives using internal disks and a H800 supporting two virtual drives in an external MD1200 enclosure. It seems that the device name (/dev/sd?) that is assigned to each virtual drive is somewhat arbitrary. It was in order of creation, but after a reboot, it changed to order of enclosure/drive. This, as you can imangine, is not a good thing. What is the best way of locking a device name to a virtual disk? udev? Thanks! Ken ___ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
