asynchronous storage replication without using SRM

[smetter]

Hello,

I was wondering,

Is it possible to use an asynchronous storage replication technology, replicating LUNs containing VMFS datastores to another site, when not using Site Recovery Manager, or do you need site recovery manager and the Site recovery Adapter (SRA)  for consistency reasons ?

We would like to use Hitachi's Truecopy Extended Distance in asynchronous mode, but without using Site Recovery Manager if possible.

[vMario156]

Of course you can use any storage replication technology without the need of using VMware SRM. That are two totally different things.

If not using SRM you just need to keep in mind that in case of a failover you need to perform some tasks manual (failover the LUNs, rescann your hosts, register all your VMs at the DR site etc.).

Regards,

Mario

[smetter]

Thanks Mario,

I'm just a bit worried about the consistency of the replicated VM data.

Apparently the aynchronous replication we would like to use works as follows:

- a point-in-time snapshot of the primary lun is taken (by the storage controller)

- this point-in-time snapshot is replicated to the secondary (replicated) lun at the other site.

- after replication is complete, a snapshot of the secondary lun is made as well to make sure

   you can return to a consistent snapshot in case the next replication would be abruptly terminated.

however, my concern is the following:

when the snapshot is taken on the primary volume (when replication starts),

this is a snapshot initiated by the storage box, but I don't think this snapshot is vmware-aware.

Shouldn't there be some kind of plugin that would be installed in vcenter that takes a snapshot of the VMs at VMware level too and coordinate this with the storage box to make sure the snapshot made for replication is consistent and that the replicated VMs will be usable ?

This is how it works for our netapp enviuronments, with some netapp vcenter plugin.

I've been taking a look into the documentation of Hitachi's extended truecopy but I didn't find any reference to a plugin for Vcenter yet that does this.

[nlevien]

The snapshot provider doesn't need to be vm aware, although I'd be surprised if Hitachi don't have a plugin that would make it vm aware.

Like you, we use NetApp snapshots to replicate our data, but we have the vm consistency option disabled.