SUMMARY: Identifying SAN devices used by Sun Cluster for migration

Thanks to Kalyan Manchikanti, Brad Morrison, Shane Gainer, Andrey Borzenkov
and DRoss-Smith for their replies. Your help is greatly appreciated.

Kaylan, Shane and Andrey suggested it might be a gatekeeper
device/controller LUN used by EMC. They also suggested to take a look at the
symmcli utility, which is not installed. The SAN appears to be a CLARiiON
(which I am admittedly not yet terribly familiar with).

DRoss-Smith suggested it might be a raw LUN used by the app. Happily, this
doesn't appear to be the case (I don't particularly like the idea of mixing
file systems and raw volumes).

Brad suggested I take a look at the LUN in format and see if I can find any
data on it. While it didn't have any file systems, I could run strings
against the raw disk device. I wound up with something like this:

[Output truncated, the last line was repeated many times]
SunCluster Quorum Area: Owner
z$SunCluster Quorum Area: Node  1
SunCluster Quorum Area: Node  1

Then I did the same thing with the currently configured quorum device, which
looked the same. So I feel comfortable concluding that this is an unused
quorum device.

If someone wants to explain the potential benefits or disadvantages of using
two quorum devices in a two-node cluster, that would be great. Otherwise I
think I'm in good shape for the migration now.

---------- Original Message ----------

I've inherited a cluster (Sun Cluster 3.1, two nodes, shared storage on EMC
with SVM, Solaris 9). We're going to be upgrading the SAN in the near
future. I'm not worried about the migration itself.

However, there are five LUNs attached to this server and I can only figure
out what four of them are! There are three file systems and the quorum
device. The unidentified LUN is also labeled on the EMC as a quorum device
and of course shows up when you run scdidadm -L, but I don't see it when I
do a scstat -q ( i.e., I only see the one quorum device I already know
about). It doesn't show up with scconf -pv or scstat -D.

There's only one metaset, and this device does not show up when I run
metastat -s. All mounted file systems exlcuding the three cluster file
systems are on local disk.

The person who built this is gone, and it's entirely possible that this last
LUN was never used. However, I need to confirm that, or figure out what the
LUN is used for so I can make sure it's migrated. Are there any other
possible purposes for a shared LUN in Sun Cluster? Any way to figure out if
it's in use?
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