On 01/09/2013 06:09 PM, Can Jeuleers wrote:

Hi,

Over the years I've had various problems with the degree to which the
adding of spares on boot is automatic. There have been times when this
has just worked, and other times (such as now) where it only works very
occasionally (or not at all). Google is full of stories like this.

I have no clue why it's not working automatically, I just know that it
isn't.

So I wrote a little script that automates this, and hooked it up to
mdmon as an event handler.

It can probably do with an elegance upgrade, but it works for me.

HTH, Jan

Here is sample output of the script, which it mails to root:

The UUID of component devices is 442e9934:97191d8e:6d0cf7a9:41621837
(442e9934-9719-1d8e-6d0c-f7a941621837)
Device /dev/sdb2 is already a member of the array
Device /dev/sdd2 is already a member of the array
Found device /dev/sde3 with the same UUID but not yet a component device.
mdadm: re-added /dev/sde3

It's a great shame that there does not appear to be a standard format
for representing UUIDs: mdadm uses an 8:8:8:8 format, whereas blkid
wants an 8-4-4-4-12 format. Hence the conversion shenanigans in the
script. Makes the code brittle.

Cheers, Jan