Saturday I did an upgrade from 5.3 (original install) to 5.4. Saturday night, /etc/cron.weekly reported the following:
/etc/cron.weekly/99-raid-check:
WARNING: mismatch_cnt is not 0 on /dev/md0
md0 holds /boot and resides, mirrored, on sda1 and sdb1. md1 holds an LVM volume containing the remaining filesytems, including swap.
The underlying hardware is just a few months hold, has passed the usual memtest stuff, and has been running 5.3 well for a few months.
I'm *guessing* that due to the timing, this is related to the upgrade. I have to admit that I forgot myself and instead of doing the glibc updates as recommended, I only did:
yum clean all yum update yum rpm -e --nodeps perl-5.8.8-18.el5_3.1.i386 (see today's perl thread) yum update perl.x86_64 yum update shutdown -r now
I've taken a backup of /boot dump after the upgrade, but have not yet reenabled normal backups.
My hunch is that something in the upgrade process touched sda1 but not sdb1, and that removing sdb1 from the mirror and reattaching it for resync would be sufficient, however I was looking for comments on this from anyone with experience or opinion on the matter. Googling the issue doesn't seem to turn up any recent related results.
Also, could the upgrade have touched the bootblock on sda1 but not sdb1 and thus trigger this problem?
Devin