Joshua Baker-LePain wrote:
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.
Yes I did do this, I copied a file to the mountpoint and did a sync. Nothing.
Only at the end of the shutdown did we see some SCSI IO errors, it tried a few times to flush and then gave up and completed the reboot.
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.
That'd for sure stress it :-) But if a cable falls out or a drive shoots out of the box high into the night sky, I would expect to hear about it at least from the logs next time I tried to write one byte.
-Andy