Yes it is "reall [that] simple". Adding two more drives to / is a bit
questionable though. You may want to reconsider that. Why not just
create another mirror and mout it on /somedir?

In any case, here are the commands you need to run after partitioning
the secondary drives:

metattach d10 c0t2d0s0
metattach d20 c0t3d0s0
metattach d0
growfs -M / /dev/md/rdsk/d0

I have done this countless times and never had an issue.


Jeffery Small wrote:
> I have a question about expanding storage on an existing SVM mirror.
>
> I am running Solaris 9 on a SunFire V250 SPARC system. I currently have
> two 73 GB drives (c0t0d0 and c0t1d0) set up as a SVM RAID 1 mirror. Each
> drive is partitioned as follows:
>
> s0 60.34 GB /
> s1 4.00 GB <swap>
> s3 4.97 MB <replica>
> s4 4.00 GB /var
> s5 4.97 MB <replica>
>
> The mirror configuration is as follows:
>
> Mirror d0: [/]
> Submirror d10
> Submirror d20
> Mirror d1: [swap]
> Submirror d11
> Submirror d21
> Mirror d4: [/var]
> Submirror d14
> Submirror d24
>
> I now have two additional 73 GB drives (c0t2d0 and c0t3d0). I intend to
> partition each of these disks with one large s0 partition which includes
> all of the available disk space. I would then like to add each as a
> concatenation to the root slice on the existing mirrored drives. After
> reading the SVM documentation and the various manual pages, I see example
> #5 in the metattach(1m) manual page which seems to be stating that the new
> disks can be added to the live mirror with the commands:
>
> metattach d10 c0t2d0s0
> metattach d20 c0t3d0s0
>
> after which, the space is then expanded using:
>
> growfs -M / /dev/md/rdsk/d0
>
> Questions:
>
> 1: Is it really this simple? At first I thought I would have to break
> the mirror, add the concatenations to d10 and d20 using metainit(1m),
> use growfs(1m) on each of the submirrors and then rebuild the mirror.
> However, since I cannot unmount the / or /var filesystems, this
> procedure was also unclear. I'm also a bit puzzled how, on a live
> system, you could concatenate/grow space on one of the mirrors while
> the other one had not yet been expanded. Is SVM simply smart enough
> to deal with this situation?
>
> 2: Other than partitioning the two new disks identically, is there any
> other disk preparation that would be required? I assume that the
> growfs(1m) will take care of expanding the filesystem across the
> new disks.
>
> 3: If the metattach method above works, is it correct to use growfs on
> the actual mirror d0 or does it have to be used on each of the d10
> and d20 submirrors? I'm concerned about getting this right as I do
> not want to clobber my existing OS.
>
> 4: Since we are messing around with the / filesystem, is there any need
> to rerun metaroot(1m) or modify the /etc/vfstab entries? (I would
> assume not.)
>
> 5: Is it necessary to update the /etc/lvm/md.tab file after these
> revisions with:
>
> metastat -p > /etc/lvm/md.tab
>
> I would assume so, but I never saw any reference to this is the
> examples.
>
> 6: Any other issues or steps I am missing?
>
> Thanks for any help you can offer.
>
> Regards,
> --
> Jeff
>
> C. Jeffery Small CJSA LLC 206-232-3338
> jeff@cjsa.com 7000 E Mercer Way, Mercer Island, WA 98040