On Sun, Feb 28, 2010 at 02:37:13PM -0800, John R Pierce wrote: > And how do I know all these mirror data mismatches are Swap? does not > each mismatch mean the mirrors disagree, which means one of them is > wrong. Which one? since they aren't timestamped or checksummed (like This thread is very timely. I updated my C5.3 to 5.4 last week (not sure why it took me so long) and this morning noticed my raid5 was resyncing. 5*1Tbyte disks. The resync took... Feb 28 04:22:02 mercury kernel: md: syncing RAID array md3 Feb 28 16:27:06 mercury kernel: md: md3: sync done. Performance was bad during this time. Not terrible from an interactive point of view, but a job that normally run from 4am to 10am didn't finish until 3pm. I like the concept of checking the disks are good, but it really sounds like there are practical problems (false positives, performance degregation) . So I think /etc/sysconfig/raid-check is going to read ENABLED=no -- rgds Stephen