Solaris

With only two disks, you use disk suite ONLY to mirror them. This will run fine. If one disk fails, mirroring won't work anymore. If you reboot, you are right, disk suite is hosed, but the system is usable anyway. When you replace a disk, you need to rebuild the mirrors.

The only real challenge is arranging to boot automaticly from the secondary submirror if the primary submirror dies. To do that, from the ok prompt, build an alias for your 2nd disk and call it disk2 or something. Then set the boot-device variable to "disk disk2".

If you put three metadbs on both disks, then you can still run if one disk fails - this has worked for over 5 years on servers I admin today. And you are right, the documentation states 3 disks.
Example from Solaris 2.6 server build:
metadb -f -c 3 -a /dev/rdsk/c0t0d0s7 /dev/rdsk/c0t1d0s7
metainit -f d10 1 1 c0t0d0s0
metainit d11 1 1 c0t1d0s0
(You can add other partitions - this is only showing /)
metaroot d1
(if you add other partitions - add them into /etc/vfstab here)
lockfs -fa (then reboot)

After reboot,
metattach d1 d11

And on Perderabo's steps, install a boot block to insure disk2 will boot.

There is no need to install a boot block on the second disk of a mirror (I´m speaking of Solaris 8/9 SPARC)

You must also (on a SPARC System) modify some OBP variables , so the server can boot automatically from the second half of the mirror. You must also specifiy the second half of the mirror as a diag device which means that coredumps are being saved there.

ok setenv boot-device disk disk1

ok setenv diag-device disk disk1

try it with

ok boot disk1

sorry Perderabo, I didn´t noticed that you ´ve already posted the OBP Stuff

networkfreak

I'm not sure why you added that Solaris 8/9 qualifier? I'm not really a Sun guy, but my understanding is as follows... The boot block is the first block on the disk. If a partition starts on Cylinder 0, the boot block is in it. If you use that partition for swap or for a filesystem, solaris knows to skip over the boot block. (Not sure about using that partition as a replica data base.) And when you mirror that partition, the boot block will get copied. I believe that this is the case with any version of solaris. I guess you probably would need to install a boot block if you didn't include include cylinder 0 in a partition. (And we have seen stranger setups )

I had always heard you need to install a boot block -
4.2 installboot
or
4.2.1 installboot (Just search for installboot on the page)