Subject: Re: raidframe copyback blocks the whole system !?
To: None <firstname.lastname@example.org>
From: Greg Oster <email@example.com>
Date: 06/25/2002 16:47:43
Markus W Kilbinger writes:
> >>>>> "Greg" == Greg Oster <firstname.lastname@example.org> writes:
> Greg> Well... if you have hot-swap drives, then you could just
> Greg> stuff the new drive in place of the old one, and not worry
> Greg> about doing a copyback.. (i.e. the new drive you put in
> Greg> becomes the hot spare).
> >> Hmm, how to come!? The old/new drive still has state 'failed',
> >> the spare is 'used_spare'. So, what will happen if another
> >> drive fails in this stage?
> Greg> You stuff another drive into the box, hot-add it, and
> Greg> rebuild to it :)
> Let's proceed: ;-)
> I just can place in a new drive in place of a failed one. -> A known,
> but 'failed' scsi id / /dev/sd.. refers to a fresh drive now. ->
> Adding this as a new spare ('raidctl -a /dev/sd..', I guess) would
> work!? (I wouldn't even dare...)
Hmm... I don't think I've ever tried exactly what you suggest :)
I have put a fresh drive (with a SCSI ID different from all other drives,
including the failed drive) into the system, and hot-added that...
I'm not sure if it would let you hot-add /dev/sd1e even after /dev/sd1e
failed, was removed, and was added back in again... (if the device was closed,
it might, but otherwise it wouldn't...)
> >> How will the 'failed' drive become the new spare _without_
> >> reboot?
> Greg> You stuff a fresh drive into that slot, and when a different
> Greg> drive fails, rebuild to the fresh drive. Not quite the same
> Greg> as a spare, but works much the same. :)
> But then you've lost the real spare / redundancy effect, because then
> the first reconstruction step (onto the spare drive), normally done
> automatically, has to be done manually, now.
Except the first reconstruction isn't done automatically right now either :-}
> -> Then it would be better to handle the complete spare drives
> manually, because there are only smooth reconstructions. Having a
> 'used_spare' means either blocking copyback or a (reordering) reboot.
> Or is 'raidctl -C ...' allowed with a used running raid!? (Another
> thing I wouldn't dare! ;-))
No.. you don't want to be doing 'raidctl -C ...'s after you get a set
configured, and it won't let you do 'raidctl -C' when it's already running.
(You really only want to do the 'raidctl -C' the first time, and then let
the autoconfig stuff do its magic after that :) )