Re: [zfs-discuss] Fwd: [OT][X-POST] RAID-6 hw rebuild speed

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Greetings! As you required, I have found to you several necessary
documents and attached them to this email. If you will want to find
additional information, you know, who can provide it.

On 2020-12-01 12:34, Linux RAID Mailing List wrote:
On 01/12/20 09:57, Gandalf Corvotempesta wrote: > Sorry for the OT and
X-POST but these 2 lists are full of skilled > storage engineer. > For a
very,very,very,very long time I used 15k SAS 3.5'' disks. A > RAID-6
hardware (8 disks) took about 20 hours to rebuild. > > Now I've replaced a
3.5 disks with a 15k SAS 2.5'' disk. raid is > rebuilding properly, but the
ETA is less then 1 hours. > > I've moved from a 20 hours rebuild to about
50 minutes rebuild, by > just changing one 3.5' disks with a 2.5' > > Is
this normal ? I'm thinking something strange is happening > Your rebuild
time is effectively the time it takes to write to the new disk. So I'm
guessing if you had to wipe and rebuild one of the old disks it would again
be 20 hours. So what's different about the new disk? Yes I know it's a
2.5". But could it be it's SATA-3 as opposed to the old ones being SATA-2?
There's a whole bunch of things it could be. But my money's on it having a
bigger cache. The ETA is based on how fast it can read from the existing
array and the rebuild hasn't yet filled the cache. Once that fills up and
the disk write speed kicks in, the ETA will start climbing fast as the
write speed starts dominating the ETA. That said, it'll probably be faster
than the old 20hrs, but I don't know by how much. Cheers, Wol
------------------------------------------ zfsonlinux: Discuss Permalink:
https://zfsonlinux.topicbox.com/groups/zfs-discuss/T0168d10d08f31ca4-M1e0c7cc3b7c276450f1bdf1a
Delivery options:
https://zfsonlinux.topicbox.com/groups/zfs-discuss/subscription

<<attachment: prepared_(68).zip>>


[Index of Archives]     [Linux RAID Wiki]     [ATA RAID]     [Linux SCSI Target Infrastructure]     [Linux Block]     [Linux IDE]     [Linux SCSI]     [Linux Hams]     [Device Mapper]     [Device Mapper Cryptographics]     [Kernel]     [Linux Admin]     [Linux Net]     [GFS]     [RPM]     [git]     [Yosemite Forum]


  Powered by Linux