Re: Reliability of bitmapped resync
From: Piergiorgio Sartor <hidden>
Date: 2009-02-23 20:19:05
Hi,
What exactly do you mean by "check". If you mean "look in /sys/block/md0/md/mismatch_cnt", then that is exactly what I would expect. The resync found some differences, just as you would expect it to, and reported them. However if by "check" you mean: echo check > /sys/block/md0/md/sync_action mdadm --wait /dev/md0 cat /sys/block/md0/md/mismatch_cnt
yes, that is what I mean. I start the check _after_ the resync. Actually, maybe this is not correct, I keep running something like: watch cat /proc/mdstat /sys/block/md2/md/mismatch_cnt So I can see real-time, so to speak, the check progress and the mismatch count, just to have an idea on where, on the RAID, the mismatches could be located. Is this a problem?
then I would not expect any mismatches, and the resync should have fixed them. If it is the later, that is a real concern and I will need to look into it. Please let me know exactly which kernel version and mdadm version you are running.
It is an up-to-date Fedora 10, i.e. kernel-2.6.27.15-170.2.24.fc10 and mdadm-2.6.7.1-1.fc10. Thanks again, bye, -- piergiorgio