Re: replacing drives

[Roberto Nunnari <roberto.nunnari@supsi.ch>]

Robin Hill wrote:
> The safest option would be:
>  - add in the new disks
>  - partition to at least the same size as your existing partitions (they
>    can be larger)
>  - add the new partitions into the arrays (they'll go in as spares)
>  - grow the arrays to 4 members (this avoids any loss of redundancy)
>  - wait for the resync to complete
>  - install grub/lilo/syslinux to the new disks

Ok.. got here.


>  - fail and remove the old disk partitions from the arrays

Now.. I may need some guidance for the next steps.. please correct me if 
I'm wrong..

to fail the old disk partition from the arrays I should:
mdadm -f /dev/md0 /dev/sda1
mdadm -f /dev/md1 /dev/sda2
mdadm -f /dev/md2 /dev/sda3
mdadm -f /dev/md0 /dev/sdc1
mdadm -f /dev/md1 /dev/sdc2
mdadm -f /dev/md2 /dev/sdc3

and to remove the old disk partition from the arrays I should:
mdadm -r /dev/md0 /dev/sda1
mdadm -r /dev/md1 /dev/sda2
mdadm -r /dev/md2 /dev/sda3
mdadm -r /dev/md0 /dev/sdc1
mdadm -r /dev/md1 /dev/sdc2
mdadm -r /dev/md2 /dev/sdc3

correct?


>  - shrink the arrays back down to 2 members

to shrink the arrays back down to two members:
mdadm --grow --raid-devices=2 /dev/md0
mdadm --grow --raid-devices=2 /dev/md1
mdadm --grow --raid-devices=2 /dev/md2

correct?

Thank you very much for your precious help!

Robi