[mythtv-users] Storage Questions. LVM, RAID, NFS

[Francois Marier]

On Mon, May 01, 2006 at 05:00:22PM -0500, Dean Wilson wrote:
> Speaking of replacing disks, how difficult is it to replace a bad disk
> with mdadm?  (And how will I know if a disk has gone bad?  Will it
> limp along, or force me to replace it immediately?)

You will be able to tell that a disk has gone bad when mdadm kicks it out of
the raid array at boot time.   It will add something to the system log and
send an email to the address in the configuration file.

To add a brand new drive back to an existing raid array, you just have to
partition the new drive and then add it to the array with a command like:
  mdadm --manage /dev/md0 -a /dev/sda1

mdadm will then take care of re-syncing the data on both drives.

That said, another thing you may want to run to check for bad disks is
smartmontools (http://smartmontools.sf.net) which monitors the self-tests
and other "health" attributes of the hard drive.  It can be very useful
since it may warn you before a disk fails completely.

Francois