I just tried to issue a few commands to a new server and received I/O errors:

# ls -la
bash: /bin/ls: Input/output error

So, I checked out /proc/mdadm and saw that one of my drives seems to have
failed:

Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md1 : active raid1 sdb1[1] sda1[0]
112320 blocks [2/2] [UU]

md3 : active raid1 sdb3[2](F) sda3[0]
308255104 blocks [2/1] [U_]

My question is, "which one?" Usually I get a [UU] on a good RAID, and an _
for the failed drive. That would indicate that sda3 has failed. However,
sdb3 is marked with an (F), which I've never seen before.

Which drive should I replace?

Also, why did I get an I/O error? Shouldn't my RAID have just failed over
silently?

Last point of information is this from /var/log/messages:

Oct 30 07:02:12 voice21 klogd: ata1: soft resetting link
Oct 30 07:02:12 voice21 klogd: ata1.00: configured for UDMA/100
Oct 30 07:02:12 voice21 klogd: ata1.01: configured for UDMA/100
Oct 30 07:02:12 voice21 klogd: ata1.00: retrying FLUSH 0xea Emask 0x4
Oct 30 07:02:12 voice21 klogd: ata1.00: device reported invalid CHS sector 0
Oct 30 07:02:12 voice21 klogd: ata1: EH complete

Thanks in advance.

--

Take care and have fun,
Mike Diehl.