I installed Ubuntu Server 10.04.2 LTS AMD64 on a HP ProLiant ML370 G3 (4 x dual-core/hyperthreaded Xeon 2.66 GHz, 8 GB RAM) and I used the on-board SCSI controller to manage 8 x 300 GB 15K RPM SCSI drives in a software RAID 5 set up as a 7-drive array with 1 hot-spare drive. All drives are the exact same model with the same firmware version.
It's currently rebuilding the array (because I just created the array) and /proc/mdstat is reporting "finish=165.7min speed=25856K/sec". Does that sound "right" in the sense that it's the right order of magnitude? I though it should be higher, but I haven't set up such an array before, so I don't have anything to compare it to.
If it's slow, does anyone have a suggestion for speeding it up?
Kevin
Linux has speed limits on rebuilds, check
/proc/sys/dev/raid/speed_limit_max /proc/sys/dev/raid/speed_limit_min
and echo new values into there.
Gerald
----- Original Message -----
I installed Ubuntu Server 10.04.2 LTS AMD64 on a HP ProLiant ML370 G3 (4 x dual-core/hyperthreaded Xeon 2.66 GHz, 8 GB RAM) and I used the on-board SCSI controller to manage 8 x 300 GB 15K RPM SCSI drives in a software RAID 5 set up as a 7-drive array with 1 hot-spare drive. All drives are the exact same model with the same firmware version.
It's currently rebuilding the array (because I just created the array) and /proc/mdstat is reporting "finish=165.7min speed=25856K/sec". Does that sound "right" in the sense that it's the right order of magnitude? I though it should be higher, but I haven't set up such an array before, so I don't have anything to compare it to.
If it's slow, does anyone have a suggestion for speeding it up?
Kevin _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Did that, no effect. Building a RAID10 array of 14 10K disks (including two hot spares, so really 12 disks) on the same controller (different channel, not at the same time as the RAID5 rebuild) gives ~130,000 KB/sec.
On Thu, May 19, 2011 at 1:57 PM, Gerald Brandt gbr@majentis.com wrote:
Linux has speed limits on rebuilds, check
/proc/sys/dev/raid/speed_limit_max /proc/sys/dev/raid/speed_limit_min
and echo new values into there.
Gerald
I installed Ubuntu Server 10.04.2 LTS AMD64 on a HP ProLiant ML370 G3 (4 x dual-core/hyperthreaded Xeon 2.66 GHz, 8 GB RAM) and I used the on-board SCSI controller to manage 8 x 300 GB 15K RPM SCSI drives in a software RAID 5 set up as a 7-drive array with 1 hot-spare drive. All drives are the exact same model with the same firmware version.
It's currently rebuilding the array (because I just created the array) and /proc/mdstat is reporting "finish=165.7min speed=25856K/sec". Does that sound "right" in the sense that it's the right order of magnitude? I though it should be higher, but I haven't set up such an array before, so I don't have anything to compare it to.
If it's slow, does anyone have a suggestion for speeding it up?
Kevin
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
Yup. That makes sense. Raid 10 does't involve a parity calculation. Raid 10 is stripe and mirror so it's single read to single write. Raid 5 is multiple reads to single write on rebuild. Comparing the two for rebuild is an apples to oranges kinda thing.
On 2011-05-19 Kevin McGregor wrote:
I installed Ubuntu Server 10.04.2 LTS AMD64 on a HP ProLiant ML370 G3 (4 x dual-core/hyperthreaded Xeon 2.66 GHz, 8 GB RAM) and I used the on-board SCSI controller to manage 8 x 300 GB 15K RPM SCSI drives in a software RAID 5 set up as a 7-drive array with 1 hot-spare drive. All drives are the exact same model with the same firmware version.
It's currently rebuilding the array (because I just created the array) and /proc/mdstat is reporting "finish=165.7min speed=25856K/sec". Does that sound "right" in the sense that it's the
I got around 20-30M/s or so on my RAID6 7200rpm 12TB 8-disk rebuild this week. That was on an old Pentium-D but with a nifty zippy new 8-port SATA card. Your speeds sound a touch slow, given the hardware. But RAID5/6 does weird things behind the scenes.
Note, if you're doing 8 drives anyhow, why not RAID6? Its survivability is much higher and its performance is surprisingly nearly that of RAID5 (there's some graphs somewhere I was recently looking at). The only downside is degraded performance sucks, but hopefully you will never be in that state (long). I've personally had/seen 2 RAID5 failures and will never use anything except RAID6 now.
Well... I wasn't sure what the best choice was, given the circumstances. This isn't an array for production, just development or (more likely) testing. And the big thing is, I'm re-using existing equipment, and I had 8 300 GB 15K RPM drives, and no further replacements handy. One can probably get those drives if need be, but the City wouldn't likely pony up the cost. So I figured I'd use only 7 drives with one spare for RAID5. I could have gone RAID6 on eight drives for the same capacity, but when one drive fails I'll be back to RAID5 (sort of) anyway.
Just out of curiosity, where would you get HP 300 GB 15K RPM "universal hot swap" drives from, and what do they cost these days? I see on eBay one listing for US$350/drive.
Kevin
On Thu, May 19, 2011 at 5:25 PM, Trevor Cordes trevor@tecnopolis.ca wrote:
On 2011-05-19 Kevin McGregor wrote:
I installed Ubuntu Server 10.04.2 LTS AMD64 on a HP ProLiant ML370 G3 (4 x dual-core/hyperthreaded Xeon 2.66 GHz, 8 GB RAM) and I used the on-board SCSI controller to manage 8 x 300 GB 15K RPM SCSI drives in a software RAID 5 set up as a 7-drive array with 1 hot-spare drive. All drives are the exact same model with the same firmware version.
It's currently rebuilding the array (because I just created the array) and /proc/mdstat is reporting "finish=165.7min speed=25856K/sec". Does that sound "right" in the sense that it's the
I got around 20-30M/s or so on my RAID6 7200rpm 12TB 8-disk rebuild this week. That was on an old Pentium-D but with a nifty zippy new 8-port SATA card. Your speeds sound a touch slow, given the hardware. But RAID5/6 does weird things behind the scenes.
Note, if you're doing 8 drives anyhow, why not RAID6? Its survivability is much higher and its performance is surprisingly nearly that of RAID5 (there's some graphs somewhere I was recently looking at). The only downside is degraded performance sucks, but hopefully you will never be in that state (long). I've personally had/seen 2 RAID5 failures and will never use anything except RAID6 now. _______________________________________________ Roundtable mailing list Roundtable@muug.mb.ca http://www.muug.mb.ca/mailman/listinfo/roundtable
On 2011-05-20 Kevin McGregor wrote:
Just out of curiosity, where would you get HP 300 GB 15K RPM "universal hot swap" drives from, and what do they cost these days? I see on eBay one listing for US$350/drive.
Adam is right, you can get pretty much any SCSI drive as long as it's the correct connector (ie: SCA vs 68-pin). I can order in many different brands/models if you ever want some pricing.
I actually just bought another 15krpm 68-pin for my main box and was surprised how cheap SCSI has become (compared to 5 years ago).
I've been quite happy with Fujitsu SCSI drives over the last 10 years, even though I've learned to loathe their IDE stuff. They usually are the cheapest, too.
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Gerald Brandt -
Kevin McGregor -
Sean Cody -
Trevor Cordes