Re: [gentoo-user] Auto-Rebuild md RAID Arrays?

[Michael Orlitzky <michael@orlitzky.com>]

On 04/19/11 17:05, Andrew Wilkinson wrote:
> Hello All,
> 
> I am in the research phase of building a Gentoo-based backup/NAS target
> using md software RAID or (maybe) btrfs or zfs.  One thing that I am not
> finding much info about is any facility for automatically rebuilding an
> array when a new, matching drive is inserted.  At this stage, the plan
> is to use four identical drives in a RAID10-style setup.
> 
> Is any here aware of the right way to configure this?

mdadm expects you to know the drive name (e.g. /dev/sdX) of the drive
you'd like to operate on. If you are real confident,

a) in your scripting abilities
b) that the new drive will have the same name as the replaced drive

then you could write a script that removes all failed drives on startup
(there's an mdadm --manage command that does that) and adds the new ones
in their place.

I probably wouldn't risk it unless you're going to mail the box to
Alaska and it would be a great inconvenience to do manually. If someone
accidentally switches two SATA cables your script could wind up doing
some damage.

Btrfs and ZFS I can't speak to.