Messages in this thread | | | Date | Thu, 4 Apr 2002 14:56:43 -0800 | From | Mike Fedyk <> | Subject | Re: Raid5 resync slow with one linear array |
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On Thu, Apr 04, 2002 at 02:03:16PM +1000, Neil Brown wrote: > On Monday April 1, mfedyk@matchmail.com wrote: > > Hi, > > > > I just setup a 4 (5 really) drive raid5 array. > > > > It is syncing up right now and nothing else is running on the system. > > > > I have three 18GB SCA scsi drives and 2x9GB linear array in a four "drive" > > raid5 array. > > > > Unfortunately, it is syncing up quite slowly. Only about 2MB/sec on a > > 40MB/sec array. The system is idle. > > > > 2.4.19-pre4-ac3 > > > > Is there something about this config that says "Don't do that!"? I've > > heard about RAID10, but not Linear+RAID5... > > echo 10000 > /proc/sys/dev/raid/speed_limit_min > > md tries to monitor the activity on the component devices and limits > rebuild activity when there appears to be other activity. > It measures "other activity" as "blocks added to kstat.dk_drive_?blk", > minus "block due to resync activity". > > When a component device is an md array, nothing gets recorded > in kstat, but lots is recorded as resync activity, so this "other > activity" appears as a negative number which, due to storage in an > unsigned long, appears rather large. > > NeilBrown
Yeah, thought it was something like that. Thanks for the explanation. I didn't see your message until I sent the other one.
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