On Thu, 3 Feb 2005, Nigel Kendrick wrote:
> Is my new 300GB RAID 1 array REALLY going to take 18936 minutes to
> sync!!???
Hi Nigel,
If SW-RAID (i.e. raidtools / mdadm) :-
You can tune kernel parameters to increase max/min speed values here:
# cat /proc/sys/dev/raid/speed_limit_max
10000
# cat /proc/sys/dev/raid/speed_limit_min
100
Set this to, say, power of 10 (or more):
# sysctl -w dev.raid.speed_limit_max=100000
# sysctl -w dev.raid.speed_limit_min=1000
Additionally tweak it further up with:
# renice -20 `pidof mdrecoveryd`
Do all this _before_ you glue up the mirror.
# dmesg
<...>
md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc.
md: using maximum available idle IO bandwith (but not more than 100000
KB/sec) for reconstruction.
<...>
# cat /proc/mdstat
<...>
md8 : active raid1 sdb5[2] sda5[0]
2096384 blocks [2/1] [U_]
[========>............] recovery = 43.2% (907584/2096384)
finish=0.3min speed=50421K/sec
<...>
Don't recommend this if your server is I/O intensive and in production
use. Massive performance degration while reconstructing.
SW-RAID rules. :-)
Regards,
Morten
--
morten tørmoen, morten at basefarm.no, +47 97 77 47 77
basefarm as, http://www.basefarm.no, +47 40 00 41 00