On Tue, 11 Apr 2006 at 6:36pm, Andy Green wrote
> Using CentOS on a server destined to have a dozen SATA drives in it. The
> server is fine, raid 5 is set up on groups of 4 SATA drives.
>
> Today we decide to disconnect one SATA drive to simulate a failure. The box
> trucked on fine... a little too fine. We waited some minutes but no problem
> was visible in /proc/mdstat or in /var/log/messages or on the console.
>
> I ran mdadm --monitor /dev/md0 and no problem was shown.
Did you try doing any I/O to the array? In my limited experience with
software RAID, it won't notice a drive missing until it tries to do
something with said drive.
To really test it, I'd disconnect the drive while you have something
disk intensive running. I like
<http://people.redhat.com/dledford/memtest.html>, which unpacks and then
diffs multiple copies of the Linux source tree. It'll have the system
stressed *and* let you know if there any problems with the array running
in degraded mode.
--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University
