[SunHELP] fsck, metadevices, and metadb replicas

[Jan Johansson]

On Wed, May 30, 2001 at 07:47:02AM -0700, Ann Waters wrote:
>I've got a couple of questions in regards to fsck and DiskSuite
>metadevices and metadb replicas.  Assume I have the following
>configuration:
>
>metadb replicas on dedicated slices /dev/rdsk/c0t0d0s5 and
>/dev/rdsk/c0t3d0s5 submirrors metadevices:	/dev/md/rdsk/d1
>on /dev/rdsk/c0t0d0s6 /dev/md/rdsk/d2 on /dev/rdsk/c0t3d0s6 full
>mirror metadevice:		/dev/md/rdsk/d10 comprised of
>/dev/md/rdsk/d1 and /dev/md/rdsk/d2.
>
>My questions are:

>1.  When fscking, will the slices housing the metadb replicas
>(c0t0d0s5 and c0t3d0s5) check out correctly?  (I'm thinking that
>those slices don't contain a true filesystem that fsck can
>handle).

Your metadb slices should be marked as wu (unmountable) in format
and as such you do not run fsck on them or mount them, they just
exist.

An idea is also to put multiple metadb's on each slice so that
you get the required three (or is it four?).

>2.  For the mirror/submirrors, do I fsck the actual slices
>(/dev/rdsk/c0t0d0s6 and /dev/rdsk/c0t3d0s6), the submirrors
>(/dev/md/rdsk/d1 and /dev/md/rdsk/d2), or the full mirror
>(/dev/md/rdsk/d10)?

This information should be in you /etc/vfstab as
/dev/md/dsk/d10 /dev/md/rdsk/d10 /mymirror

If so fsck /mymirror will correctly fsck /dev/md/rdsk/d10 and
mount /mymirror will correctly mount /dev/md/dsk/d10.


p.s. And please teach your mail client to wrap at 65 characters.
d.s.