On Mon, 2 Nov 1998, Jorj Bauer wrote:
> Are there any plans for the ability to add and remove mirrors on the fly?
>
> I can think of one particular situation where this would be exceptionally
> useful. On a busy mail machine, it's difficult to get a static backup of
> the contents of /var/spool/mail. If the raid tools supported the ability
> to add and remove mirrors on the fly, one could have a redundant (third)
> mirror which is detached nightly, mounted as a standalone filesystem
> elsewhere, backed up, unmounted, and reattached to the /var/spool/mail
> mirror.
i see. Yep, you can sortof do this, via a simple trick. You cannot remove
a 'working' disk currently, but your above description justifies it ...
the trick is: make the disk fail. The simplest way is to use somthing like
this:
echo "scsi remove-single-device 0 0 3 0" >/proc/scsi/scsi
(the numbers identify the SCSI disk). I will add explicit support (with
apropriate safeguards) for working-disk removal. It's really simple, it's
just not there yet because there was no reason.
-- mingo
