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VPLEX with VNX backend and snapshots
Hi!
To start with, i'd like to know if it's possible to use both the regular LUN and the snapshot LUN from a VNX in a VPLEX.
I can see both LUNs, but only one storage volume.
Now, i can understand why this would happen. The snapshot LUN basically has the same identity as the regular LUN.
But is this still possible in any way?
We'd really like to be able to use all the nifty features of our VNX hardware, such as snapshotting, cloning and everything.
But with VPLEX in the mix, we instantly lose all those features AFAICT right now.
Also, the VMWare guys are asking about using VAAI as well. I think this is a similar issue. The VNX supports VAAI no problem.
Thanks in advance.
DA
117 Posts
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March 8th, 2012 03:00
If you encapsulate a LUN into a VPLEX with Application Concistent attribute, VPLEX will not make any changes to the LUN and would only allow one extent consisting of the entire volume. In that scenario, the LUN structure is exactly the same as it was before virtualization. You should be able to use array-based clones and snapshots. You can even replicate VNX LUNs with RecoverPoint to another location, which does not have VPLEX.
Cihl
15 Posts
0
March 8th, 2012 04:00
Okay. I understand how that would work.
But would it be possible to also present the snapshot through the same VPLEX?
Would i be able to write to the snapshot and/or perform roll-backs/roll-forwards safely to effect the primary LUN, as the VNX allows?
jeffwade_96e6ca
16 Posts
1
March 8th, 2012 09:00
EMC is targeting Vplex VAAI support in June of this year. I would expect the announcement to come out in May at EMC World.
Jeff Wade – EMC Customer
Cihl
15 Posts
0
March 8th, 2012 23:00
I hope it's for real this time. It was supposed to come out on 2011Q3 before.
Any idea how it's going to work? Is the VPLEX going to talk to the VNX directly for VAAI and snapshots and such?
Thanks.
RickBrunner1
117 Posts
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March 15th, 2012 15:00
Cihl,
Over the next several releases we will be adding several VAAI primitives and yes it is for real
, contact your local account team and they can provide the details on what is comming in the may/june release.
To your question of using VNX snaps, clones functions behind VPLEX, yes you can use them today assuming you utilize 1:1 encapsulation of volumes from the backend array through to the host.
stephenblanchar
1 Message
0
October 31st, 2013 09:00
Rick,
Re Snapshots of VNX LUNS through VPLEX. If we want to make use of Oracles Hot Backup functionality (alter database startbackup; alter database stop backup) then it is a simple thing to script some VNX snapshots using the cli. However if our VPLEX is between our VNX5500 and the Windows Cluster Oracle Hosts will we have to do anything on the VPLEX to ensure consistency when taking or restoring the snapshots (e.g. purge Read Cache on the VPLEX).
Thanks
Stephen Blanchard
EMC Customer U.K.
RickBrunner1
117 Posts
0
October 31st, 2013 14:00
Stephen,
On making a snapshot, no. VPLEX-Local/Metro does not cache writes, so if the host got an acknowledgement the array has the data.
If you will use it to restore, then you would want to invalidate VPLEX cache as part of the process so that once the host volumes are remounted and access data you do not have stale data being provided by VPLEX out of read cache.
In the past you would simply remove the volume or host from the VPLEX view, with VPLEX 5.2 you have a specific command (cache-invalidate) that can be used to invalidate cache from the CLI or API.
-rick