My new company uses clustering, but no one really knows what they are doing.
I am new to it myself, but I'm doing an Exchange DR review and want to plug
the holes.
The clusters are wonderful, we use SAN based clusters with Dell hardware.
We have about 10 2-node active/passive clusters total. They work great,
failover beautifully and I am now in love with clustering, especially for
Exchange.
The scary question is this: What happens if we shut down the nodes on the
clusters (or lose power or something) and when we go to start them neither
one works. In other words, what if we have to restore from backup...can we
do it?
From my current reading, the answer would be no, because we are not backing
up anything other than the stores at the moment.
The information out there on recovering an entire cluster is sketchy at
best. The Exchange DR Ops guide suggests that all that is needed is a system
state, but when I try to test this using a VMWARE SCSI based cluster,
restoring the System state onto a fresh OS install results in the cluster
service failing to start.
There are hints in that and other locations that what is needed is an ASR
(for the disk signatures). This is fine (and I am in the process of testing)
but seems impractical for an enterprise backup solution. We are using
BackupExec here at the moment and contemplating switching to Commvault.
AFAIK, neither of these do ASR backups, so we'd have to manually run an ASR
backup on each cluster (the Active node at least). And what about the
floppy? Or excluding certain files from the backup? The ASR option just
doesn't make practical sense in a production environment.
What am I missing here? How do most enterprises do their cluster backups?
Thanks for any input...
-JC
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