Re: How many drives are bad?
On Tue, 19 Feb 2008 14:25:28 -0500, Norman Elton [EMAIL PROTECTED] said: [ ... ] normelton The box presents 48 drives, split across 6 SATA normelton controllers. So disks sda-sdh are on one controller, normelton etc. In our configuration, I run a RAID5 MD array for normelton each controller, then run LVM on top of these to form normelton one large VolGroup. Pure genius! I wonder how many Thumpers have been configured in this well thought out way :-). BTW, just to be sure -- you are running LVM in default linear mode over those 6 RAID5s aren't you? normelton I found that it was easiest to setup ext3 with a max normelton of 2TB partitions. So running on top of the massive normelton LVM VolGroup are a handful of ext3 partitions, each normelton mounted in the filesystem. Uhm, assuming 500GB drives each RAID set has a capacity of 3.5TB, and odds are that a bit over half of those 2TB volumes will straddle array boundaries. Such attention to detail is quite remarkable :-). normelton This less than ideal (ZFS would allow us one large normelton partition), That would be another stroke of genius! (especially if you were still using a set of underlying RAID5s instead of letting ZFS do its RAIDZ thing). :-) normelton but we're rewriting some software to utilize the normelton multi-partition scheme. Good luck! - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Pure genius! I wonder how many Thumpers have been configured in this well thought out way :-). I'm sorry I missed your contributions to the discussion a few weeks ago. As I said up front, this is a test system. We're still trying a number of different configurations, and are learning how best to recover from a fault. Guy Watkins proposed one a few weeks ago that we haven't yet tried, but given our current situation... it may be a good time to give it a shot. I'm still not convinced we were running a degraded array before this. One drive mysteriously dropped from the array, showing up as removed but not failed. We did not receive the notification that we did when the second actually failed. I'm still thinking its just one drive that actually failed. Assuming we go with Guy's layout of 8 arrays of 6 drives (picking one from each controller), how would you setup the LVM VolGroups over top of these already distributed arrays? Thanks again, Norman On Feb 20, 2008, at 2:21 AM, Peter Grandi wrote: On Tue, 19 Feb 2008 14:25:28 -0500, Norman Elton [EMAIL PROTECTED] said: [ ... ] normelton The box presents 48 drives, split across 6 SATA normelton controllers. So disks sda-sdh are on one controller, normelton etc. In our configuration, I run a RAID5 MD array for normelton each controller, then run LVM on top of these to form normelton one large VolGroup. Pure genius! I wonder how many Thumpers have been configured in this well thought out way :-). BTW, just to be sure -- you are running LVM in default linear mode over those 6 RAID5s aren't you? normelton I found that it was easiest to setup ext3 with a max normelton of 2TB partitions. So running on top of the massive normelton LVM VolGroup are a handful of ext3 partitions, each normelton mounted in the filesystem. Uhm, assuming 500GB drives each RAID set has a capacity of 3.5TB, and odds are that a bit over half of those 2TB volumes will straddle array boundaries. Such attention to detail is quite remarkable :-). normelton This less than ideal (ZFS would allow us one large normelton partition), That would be another stroke of genius! (especially if you were still using a set of underlying RAID5s instead of letting ZFS do its RAIDZ thing). :-) normelton but we're rewriting some software to utilize the normelton multi-partition scheme. Good luck! - To unsubscribe from this list: send the line unsubscribe linux- raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
On Thu, 21 Feb 2008 13:12:30 -0500, Norman Elton [EMAIL PROTECTED] said: [ ... ] normelton Assuming we go with Guy's layout of 8 arrays of 6 normelton drives (picking one from each controller), Guy Watkins proposed another one too: «Assuming the 6 controllers are equal, I would make 3 16 disk RAID6 arrays using 2 disks from each controller. That way any 1 controller can fail and your system will still be running. 6 disks will be used for redundancy. Or 6 8 disk RAID6 arrays using 1 disk from each controller). That way any 2 controllers can fail and your system will still be running. 12 disks will be used for redundancy. Might be too excessive!» So, I would not be overjoyed with either physical configuration, except in a few particular cases. It is very amusing to read such worries about host adapter failures, and somewhat depressing to see too excessive used to describe 4+2 parity RAID. normelton how would you setup the LVM VolGroups over top of normelton these already distributed arrays? That looks like a trick question, or at least an incorrect question; because I would rather not do anything like that except in a very few cases. However, if one wants to do a bad thing in the least bad way, perhaps a volume group per array would be least bad. Going back to your original question: «So... we're curious how Linux will handle such a beast. Has anyone run MD software RAID over so many disks? Then piled LVM/ext3 on top of that?» I haven't because it sounds rather inappropriate to me. «Any suggestions?» Not easy to respond without a clear statement of what the array be used for: RAID levels and file systems are very anisotropic in both performance an resilience, so a particular configuration may be very good for something but not for something else. For example a 48 drive RAID0 with 'ext2' on top would be very good for some cases, but perhaps not for archival :-). In general, I'd use RAID10 (http://WWW.BAARF.com/), RAID5 in very few cases and RAID6 almost never. In general current storage practices do not handle that well large single computer storage pools (just consider 'fsck' times) and beyond 10TB I reckon that currently only multi-host parallel/cluster file systems are good enough, for example Lustre (for smaller multi TB filesystem I'd use JFS or XFS). But then Lustre can be also used on a single machine with multiple (say 2TB) block devices, and this may be the best choice here too if a single virtual filesystem is the goal: http://wiki.Lustre.org/index.php?title=Lustre_Howto - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Peter Grandi wrote: In general, I'd use RAID10 (http://WWW.BAARF.com/), RAID5 in Interesting movement. What do you think is their stance on Raid Fix? :) - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
On Tuesday February 19, [EMAIL PROTECTED] wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? The array is configured for 8 devices, but on 6 are active. So you have lost data. Of the two missing devices, one is still in the array and is marked as fault. One is simply not present at all. Hence Failed Devices: 1. i.e. there is one failed device in the array. It looks like you have been running a degraded array for a while (maybe not a long while) and the device has then failed. mdadm --monitor will send you mail if you have a degraded array. NeilBrown This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Neil, Is this a bug? Also, I have a question for Norman-- how come your drives are sda[a-z]1? Typically it is /dev/sda1 /dev/sdb1 etc? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: But why do two show up as removed?? I would expect /dev/sdal1 to show up someplace, either active or failed. Any ideas? Thanks, Norman On Feb 19, 2008, at 12:31 PM, Justin Piszcz wrote: How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
But why do two show up as removed?? I would expect /dev/sdal1 to show up someplace, either active or failed. Any ideas? Thanks, Norman On Feb 19, 2008, at 12:31 PM, Justin Piszcz wrote: How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux- raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Justin, This is a Sun X4500 (Thumper) box, so it's got 48 drives inside. /dev/sd[a-z] are all there as well, just in other RAID sets. Once you get to /dev/sdz, it starts up at /dev/sdaa, sdab, etc. I'd be curious if what I'm experiencing is a bug. What should I try to restore the array? Norman On 2/19/08, Justin Piszcz [EMAIL PROTECTED] wrote: Neil, Is this a bug? Also, I have a question for Norman-- how come your drives are sda[a-z]1? Typically it is /dev/sda1 /dev/sdb1 etc? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: But why do two show up as removed?? I would expect /dev/sdal1 to show up someplace, either active or failed. Any ideas? Thanks, Norman On Feb 19, 2008, at 12:31 PM, Justin Piszcz wrote: How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Norman, I am extremely interested in what distribution you are running on it and what type of SW raid you are employing (besides the one you showed here), are all 48 drives filled, or? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: Justin, This is a Sun X4500 (Thumper) box, so it's got 48 drives inside. /dev/sd[a-z] are all there as well, just in other RAID sets. Once you get to /dev/sdz, it starts up at /dev/sdaa, sdab, etc. I'd be curious if what I'm experiencing is a bug. What should I try to restore the array? Norman On 2/19/08, Justin Piszcz [EMAIL PROTECTED] wrote: Neil, Is this a bug? Also, I have a question for Norman-- how come your drives are sda[a-z]1? Typically it is /dev/sda1 /dev/sdb1 etc? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: But why do two show up as removed?? I would expect /dev/sdal1 to show up someplace, either active or failed. Any ideas? Thanks, Norman On Feb 19, 2008, at 12:31 PM, Justin Piszcz wrote: How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: How many drives are bad?
Justin, There was actually a discussion I fired off a few weeks ago about how to best run SW RAID on this hardware. Here's the recap: We're running RHEL, so no access to ZFS/XFS. I really wish we could do ZFS, but no luck. The box presents 48 drives, split across 6 SATA controllers. So disks sda-sdh are on one controller, etc. In our configuration, I run a RAID5 MD array for each controller, then run LVM on top of these to form one large VolGroup. I found that it was easiest to setup ext3 with a max of 2TB partitions. So running on top of the massive LVM VolGroup are a handful of ext3 partitions, each mounted in the filesystem. This less than ideal (ZFS would allow us one large partition), but we're rewriting some software to utilize the multi-partition scheme. In this setup, we should be fairly protected against drive failure. We are vulnerable to a controller failure. If such a failure occurred, we'd have to restore from backup. Hope this helps, let me know if you have any questions or suggestions. I'm certainly no expert here! Thanks, Norman On 2/19/08, Justin Piszcz [EMAIL PROTECTED] wrote: Norman, I am extremely interested in what distribution you are running on it and what type of SW raid you are employing (besides the one you showed here), are all 48 drives filled, or? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: Justin, This is a Sun X4500 (Thumper) box, so it's got 48 drives inside. /dev/sd[a-z] are all there as well, just in other RAID sets. Once you get to /dev/sdz, it starts up at /dev/sdaa, sdab, etc. I'd be curious if what I'm experiencing is a bug. What should I try to restore the array? Norman On 2/19/08, Justin Piszcz [EMAIL PROTECTED] wrote: Neil, Is this a bug? Also, I have a question for Norman-- how come your drives are sda[a-z]1? Typically it is /dev/sda1 /dev/sdb1 etc? Justin. On Tue, 19 Feb 2008, Norman Elton wrote: But why do two show up as removed?? I would expect /dev/sdal1 to show up someplace, either active or failed. Any ideas? Thanks, Norman On Feb 19, 2008, at 12:31 PM, Justin Piszcz wrote: How many drives actually failed? Failed Devices : 1 On Tue, 19 Feb 2008, Norman Elton wrote: So I had my first failure today, when I got a report that one drive (/dev/sdam) failed. I've attached the output of mdadm --detail. It appears that two drives are listed as removed, but the array is still functioning. What does this mean? How many drives actually failed? This is all a test system, so I can dink around as much as necessary. Thanks for any advice! Norman Elton == OUTPUT OF MDADM = Version : 00.90.03 Creation Time : Fri Jan 18 13:17:33 2008 Raid Level : raid5 Array Size : 6837319552 (6520.58 GiB 7001.42 GB) Device Size : 976759936 (931.51 GiB 1000.20 GB) Raid Devices : 8 Total Devices : 7 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Mon Feb 18 11:49:13 2008 State : clean, degraded Active Devices : 6 Working Devices : 6 Failed Devices : 1 Spare Devices : 0 Layout : left-symmetric Chunk Size : 64K UUID : b16bdcaf:a20192fb:39c74cb8:e5e60b20 Events : 0.110 Number Major Minor RaidDevice State 0 6610 active sync /dev/sdag1 1 66 171 active sync /dev/sdah1 2 66 332 active sync /dev/sdai1 3 66 493 active sync /dev/sdaj1 4 66 654 active sync /dev/sdak1 5 005 removed 6 006 removed 7 66 1137 active sync /dev/sdan1 8 66 97- faulty spare /dev/sdam1 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: How many drives are bad?
The box presents 48 drives, split across 6 SATA controllers. So disks sda-sdh are on one controller, etc. In our configuration, I run a RAID5 MD array for each controller, then run LVM on top of these to form one large VolGroup. I might be missing something here, and I realise you'd lose 8 drives to redundancy rather than 6, but wouldn't it have been better to have 8 arrays of 6 drives, each array using a single drive from each controller? That way a single controller failure (assuming no other HD failures) wouldn't actually take any array down? I do realise that 2 controller failures at the same time would lose everything. Steve. No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.7/1286 - Release Date: 18/02/2008 18:49 - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: How many drives are bad?
} -Original Message- } From: [EMAIL PROTECTED] [mailto:linux-raid- } [EMAIL PROTECTED] On Behalf Of Steve Fairbairn } Sent: Tuesday, February 19, 2008 2:45 PM } To: 'Norman Elton' } Cc: linux-raid@vger.kernel.org } Subject: RE: How many drives are bad? } } } } The box presents 48 drives, split across 6 SATA controllers. } So disks sda-sdh are on one controller, etc. In our } configuration, I run a RAID5 MD array for each controller, } then run LVM on top of these to form one large VolGroup. } } } I might be missing something here, and I realise you'd lose 8 drives to } redundancy rather than 6, but wouldn't it have been better to have 8 } arrays of 6 drives, each array using a single drive from each } controller? That way a single controller failure (assuming no other HD } failures) wouldn't actually take any array down? I do realise that 2 } controller failures at the same time would lose everything. Wow. Sounds like what I said a few months ago. I think I also recommended RAID6. Guy } } Steve. } } No virus found in this outgoing message. } Checked by AVG Free Edition. } Version: 7.5.516 / Virus Database: 269.20.7/1286 - Release Date: } 18/02/2008 18:49 } } } - } To unsubscribe from this list: send the line unsubscribe linux-raid in } the body of a message to [EMAIL PROTECTED] } More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
