The last administrator setup our production database to use 2 X 13 disk raid groups. It worked ok for about 1.5 years. However, I recently was re-organizing and decided to be safer and went to 3 X 9 disk raid groups.
Besides taking longer to rebuild, the performance during rebuild was a big issue to me - we were already pounding the disks very hard, with disk utilization going to over 90% utilization frequently. If a disk goes out during peak hours, performance could degrade very substantially and it is just a problem that I do not need. So take that into consideration as well.
Derek
-----Original Message----- From: Tavis Gustafson [mailto:tavis@hq.newdream.net] Sent: Thursday, October 21, 2004 12:29 PM To: toasters@mathworks.com Subject: raidsize recommendations
I usually setup my filers with raidsize=7 having no more than 7 disks per volume. However, I would like create a raidsize=13 volume. The only risk i can glean from NOW is that rebuild time will increase and thus increase the chances of a second drive failure (during rebuild).
Has anyone had any real world issues with using volumes of raidsize > 10
thanks, -Tavis
This system is an F840 with 1 DS14 of 144GB disks. So I guess it would be better to have one volume across two raid groups.
thanks for all the information.
On Thu, Oct 21, 2004 at 01:45:15PM -0700, Derek Lai wrote:
The last administrator setup our production database to use 2 X 13 disk raid groups. It worked ok for about 1.5 years. However, I recently was re-organizing and decided to be safer and went to 3 X 9 disk raid groups.
Besides taking longer to rebuild, the performance during rebuild was a big issue to me - we were already pounding the disks very hard, with disk utilization going to over 90% utilization frequently. If a disk goes out during peak hours, performance could degrade very substantially and it is just a problem that I do not need. So take that into consideration as well.
Derek
-----Original Message----- From: Tavis Gustafson [mailto:tavis@hq.newdream.net] Sent: Thursday, October 21, 2004 12:29 PM To: toasters@mathworks.com Subject: raidsize recommendations
I usually setup my filers with raidsize=7 having no more than 7 disks per volume. However, I would like create a raidsize=13 volume. The only risk i can glean from NOW is that rebuild time will increase and thus increase the chances of a second drive failure (during rebuild).
Has anyone had any real world issues with using volumes of raidsize > 10
thanks, -Tavis
Which is one reason why diagonal parity seems attractive to me. I have raid rebuild priority set to 'highest' currently because I don't want to trade performance for an ncreased risk of data loss. If we were using raid_dp, however, I could probably get away with turning rebuild priority to low (at least for a single disk failure), and hopefully maintain adequate performance during our peak hours even with a degraded volume. Don't have enough free disks to try this now, however. :(
On Thu, 21 Oct 2004, Derek Lai wrote:
The last administrator setup our production database to use 2 X 13 disk raid groups. It worked ok for about 1.5 years. However, I recently was re-organizing and decided to be safer and went to 3 X 9 disk raid groups.
Besides taking longer to rebuild, the performance during rebuild was a big issue to me - we were already pounding the disks very hard, with disk utilization going to over 90% utilization frequently. If a disk goes out during peak hours, performance could degrade very substantially and it is just a problem that I do not need. So take that into consideration as well.
Derek
-----Original Message----- From: Tavis Gustafson [mailto:tavis@hq.newdream.net] Sent: Thursday, October 21, 2004 12:29 PM To: toasters@mathworks.com Subject: raidsize recommendations
I usually setup my filers with raidsize=7 having no more than 7 disks per volume. However, I would like create a raidsize=13 volume. The only risk i can glean from NOW is that rebuild time will increase and thus increase the chances of a second drive failure (during rebuild).
Has anyone had any real world issues with using volumes of raidsize > 10
thanks, -Tavis
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