[Sunhelp] Disk mirroring

[Tim Conrad]

if I can ever get it back off of the drive it's on...

I have a shell script that automagically builds a mirror. It could easily be
incorperated into say, JumpStart. (Which is exactly what I used it for)

It does have some caveats, however. Since I was installing 25 of the exact same
machines, it doesn't take into account for a box to have say, 4 drives. I used
it on a box with 4 drives, and it mirrored drives 1 and 3 i nstead of 1 and 2.
Which, I suppose is just fine, but could lead to issues when you have  a drive
failure.

It also is quite dumb on how it creates the /etc/vfstab. And, the mount points
are hard-coded.

It does, though, do the reboot and build the second part of the mirrors.

However!

If you are interested in it, let me know.

Tim Conrad

Mariappan M wrote:

> Here u go. Document for Disksuite is available in docs.sun.com as pdf files.
> I heard there is a bug when we u use gui. Its better to do in command line
> mode..
>
> Mari
>
> Example - SPARC: Creating a Mirror From root (/)
> # metainit -f d11 1 1 c0t3d0s0
> d11: Concat/Stripe is setup
> # metainit d12 1 1 c1t3d0s0
> d12: Concat/Stripe is setup
> # metainit d10 -m d11
> d10: Mirror is setup
> # metaroot d10
> # lockfs -fa
> # reboot
> ...
> # metattach d10 d12
> d10: Submirror d12 is attached
> # ls -l /dev/rdsk/c1t3d0s0
> lrwxrwxrwx   1 root     root          88 Feb  8 15:51 /dev/rdsk/c1t3d0s0 ->
> ../../devices/iommu at f,e0000000/vme at f,df010000/SUNW,pn at 4d,1080000/ipi3sc at 0,0/i
> d at 3,0:a,raw
>
> ------------------
> Example - Creating a Mirror From /usr
>
> # metainit -f d12 1 1 c0t3d0s6
> d12: Concat/Stripe is setup
> # metainit d22 1 1 c1t0d0s6
> d22: Concat/Stripe is setup
> # metainit d2 -m d12
> d2: Mirror is setup
> (Edit the /etc/vfstab file so that /usr references the mirror)
> # reboot
> ...
> # metattach d2 d22
> d2: Submirror d22 is attached
>
> The -f option forces the creation of the first concatenation, d12, which
> contains the mounted file system /usr on /dev/dsk/c0t3d0s6. The second
> concatenation, d22, is created from /dev/dsk/c1t0d0s6. (This slice must be
> the same size or greater than that of d12.) The metainit command with the -m
> option creates the one-way mirror d2 using the concatenation containing
> /usr. Next, the /etc/vfstab file must be edited to change the entry for /usr
> to reference the mirror. For example, the following line:
>
> /dev/dsk/c0t3d0s6 /dev/rdsk/c0t3d0s6 /usr ufs 1 yes -
>
> should be changed to:
>
> /dev/md/dsk/d2 /dev/md/rdsk/d2 /usr ufs 1 yes -
>
> After a reboot, the second submirror d22 is attached to the mirror, causing
> a mirror resync. (The system verifies that the concatenations and the mirror
> are set up, and that submirror d22 is attached.)
>
> Example - Creating a Mirror From swap
>
> # metainit -f d11 1 1 c0t0d0s1
> d11: Concat/Stripe is setup
> # metainit d21 1 1 c1t0d0s1
> d21: Concat/Stripe is setup
> # metainit d1 -m d11
> d1: Mirror is setup
> (Edit the /etc/vfstab file so that swap references the mirror)
> # reboot
> ...
> # metattach d1 d21
> d1: Submirror d21 is attached
>
> The -f option forces the creation of the first concatenation, d11, which
> contains the mounted file system swap on /dev/dsk/c0t0d0s1. The second
> concatenation, d21, is created from /dev/dsk/c1t0d0s1. (This slice must be
> the same size or greater than that of d11.) The metainit command with the -m
> option creates the one-way mirror d1 using the concatenation containing
> swap. Next, if there is an entry for swap in the /etc/vfstab file, it must
> be edited to reference the mirror. For example, the following line:
>
> /dev/dsk/c0t0d0s1 - - swap - no -
>
> should be changed to:
>
> /dev/md/dsk/d1 - - swap - no -
>
> After a reboot, the second submirror d21 is attached to the mirror, causing
> a mirror resync. (The system verifies that the concatenations and the mirror
> are set up, and that submirror d21 is attached.)
>
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