Re: raid1 issue, somewhat related to recent "debian on big machines"

[Goswin von Brederlow <goswin-v-b@web.de>]

lsorense@csclub.uwaterloo.ca (Lennart Sorensen) writes:

> On Tue, Mar 03, 2009 at 10:59:50PM +0100, Francesco Pietra wrote:
>> I understand that the double recommendation is fine. Though, I am
>> pressed by answering the referees about a submitted paper as they
>> requested additional computation. That was going on until the host
>> suspended access to sda. As I find risky to go on with one disk only
>> (for a many days computation), could you please explain how to
>> reactivate the removed sda, or format it to try if it recovers? I made
>> some proposals in previous post. Or indicated that the best is
>> replacing the disk with a new one.
>
> You can simply ask mdadm to readd it back and let it rebuild, but likely
> the error will happen again and you will need to replace the disk.
>
> If you replace the disk (with a disk at least as big as the old one),

If you do have hotplug support then don't forget to mdadm --remove sda
form all raids before pulling the disk.

> then copy the partition table from the working drive and reread the
> partition table (hdparm -z /dev/sda can do that for you) and finally
> readd to the various raids again.  You do not need to create a filesystem,
> since the filesystem runs on the raid, not the individual partitions,
> and hence you already have your filesystems made.

MfG
        Goswin