Subject: Re: RAID advice please ?
To: Jason R Thorpe <>
From: Thor Lancelot Simon <>
List: current-users
Date: 04/06/2000 17:56:46
On Thu, Apr 06, 2000 at 09:38:18AM -0700, Jason R Thorpe wrote:
> On Thu, Apr 06, 2000 at 06:17:11PM +0200, Manuel Bouyer wrote:
>  > For now I added a 'raidctl -P raid0' call in /etc/rc just before fsck,
>  > but the problem is that after an unclean shutdown it will take a very
>  > long time to reboot, because it'll have to revrite the parity before
>  > starting fsck. As I'll have about 10 raid1 sets on the machine this
>  > is not very good.
> Well, RAID-1 (mirroring only) shouldn't need a parity rewrite anyhow.  What
> am I missing here?

You're missing that the mirror halves (a.k.a "parity" in this case) might
be out of sync.  Until you know they're in sync, you can't safely read from
one of them.