ZFS, SAN's, HA, Possible?

Question

I currently work for a company that has purchased a number of different SAN solutions (whatever was cheap at the time!) and i want to setup a HA ZFS file store over fiber channel.

Basically I've taken slices from each of the sans and added them to a ZFS pool on this box (which I'm calling a 'ZFS proxy'). I've then carved out LUN's from this pool and assigned them to other servers. I then have snapshots taken on each of the LUN's and replication off site for DR. This all works perfectly (backups for ESXi!)

However, I'd like to be able to a) expand and b) make it HA. All the documentation i can find on setting up a HA cluster for file stores replicates data from 2 servers and then serves from these computers (i trust the SAN's to take care of the data and don't want to replicate anything -- cost!). Basically all i want is for the node that serves the ZFS pool to be HA (if this was to be put into production we have around 128tb and are looking to expand to a pb). We have a couple of IBM SVC's that seem to handle the HA node setup in some obscure property IBM way so logically it seems possible.

Clients would only be making changes via a single 'zfs proxy' at a time (multi-pathing setup for fail over only) so i don't believe I'd need to OCFS the setup? If i do need to setup OCFS can i put ZFS on top of that? (want snap-shotting/rollback and replication to a off site location, as well as all the goodness of thin provisioning and de-duplication)

However when i import the ZFS pool onto the 2nd box i got large warnings about it being mounted elsewhere and i needed to force the import, then when importing the LUN's i saw that the GUUID was different so multi-pathing doesn't pick that the LUN's are the same? can i change a GUUID via smtfadm? Is any of this even possible over fiber channel? Is anyone able to point me at some documentation? Am i simply crazy?

Any input would be most welcome.

Thanks in advance,

Answer 1

I know that Nexenta does HA by using RSF-1 from http://high-availability.com/ - something you may want to consider is actually getting two NexentaStor head nodes which would bring all this goodness to you. If you're in the UK take a look at http://www.va-technologies.com/

Answer 2

If you want HA with ZFS, the only two methods I know of are:

• Nexenta HA Cluster
• Sun 7000 Series (Fishworks)

Basically with either setup, you have two matching head units which either a) store a redundant copy of each block b) can access each others JBODs for failover. But the real answer is talk to a vendor, pick a recommended solution and buy a support contract. Otherwise when issues inevitably arise you're going to be on your own. What's the point of setting up HA, making everything you can think of redundant, yet leaving yourself as a single point of failure.

Answer 3

You can't do ZFS on top of OCFS, they're both file systems. As for the issues with sharing ZFS pools - well look at my response to one of your other many, very similar questions from the last few days where I explain this is because ZFS isn't cluster-aware and you'll just corrupt your pools.