I need a bit of a reminder about using San Copy on vmfs formatted luns

[MrBiscuit]

Howdy all,

Pre-information: This is an environment I've just inherited warts and all so bear with me. I've got a CX300 and a CX500 hooked together and a San Copy session setup to comfortably pull a copy of a Lun from the Cx3 to the Cx5 which has never been tested. The client was sold San Copy as the solution to their replication needs, but I suspect this was without the additional information required to make it entirely useful.

Firstly, am I correct in remembering that I cannot San Copy a mounted (ie powered-on vm guests stored in it) Lun without risking dropping the attached hosts and therefore crashing the live vm guests? I realise I would end up with a crash consistant copy anyway if I did this, but I'm hoping they can hot-copy safely and fix afterwards.

Is there a workaround for the above by perhaps using SnapView on the Lun, San Copying that (if you can?) and the recovering the crash consistant vmdks?

As they have directly formatted their Luns as VMFS with no RDM used, am I also correct in stating that the all VM's in the LUN must be powered off to get a non-crash consistant copy of the LUN such as might be used for DR purposes? I recall with RDM mapped drives you can quiesce the guests and snap the LUN safely.

Lastly, if anyone is using a similar configuration, or has a recommendation for the best DR-oriented replication I can achieve in this scenario without spending extra budget I would appreciate hearing it. I believe there are also FC to IP converters in a box around here somewhere with plans to move one of the Sans to a sister site and tie in a fast transit between them so that is also under consideration. I have no problem with rebuilding the Luns to RDM as there aren't that many guests on there, but I'm uncertain if this would be the best way forward.

Thanks in advance.

[Rodos]

I am no EMC SAN expert (he is two partitions over).

You can't do a SanCopy of the live LUN, it must be off a snap. If when the SAN snap executes the VM's have not all done their own snap you will only be crash consistent.Some people create scripts to initiate snaps on the VMs on the LUN before the SAN snap, others just live with the crash consistency.

You don't need to power off all the VMs to get crash consistent. If you were to power them all off before the snap/sancopy they would all be full consistent copies.

How to achieve the best solution without spending extra budget ... um ... why don't you ask something easy like world hunger. LOL.

[MrBiscuit]

You can't do a SanCopy of the live LUN, it must be off a snap. If when the SAN snap executes the VM's have not all done their own snap you will only be crash consistent.Some people create scripts to initiate snaps on the VMs on the LUN before the SAN snap, others just live with the crash consistency.

Unfortunately the live data is on the CX300 and therefore no snaps available; I shall have to organise downtime to migrate it to it's new home on the CX500, this is not unexpected

What I mean by 'best solution' is the best I can reasonably achieve with this current set of hardware and tools, you have touched on what I was thinking with the use of scripts, snaps and san copy based on the CX500 to push to the CX300 at the remote site as the DR device. I highly suspect that once I have this working, and can point out it's short comings, I will be able to wrangle budget for something more fit-for-purpose like Vizioncores' offerings.

[Dunnib]

Hi Everyone,

Small disclainmer first that I am an EMC employee.

EMC just announced at EMC World the release of Replication Manager 5.1 sp2. This is huge for us Vmware users. Replication manager will now support VM consistant snaps and clones of VMFS volumes in addition to Individual VM restores from those snaps and clones. You will have the ability to perform a VM snap prior to cloning or snapping the VMFS lun. You will then be able to mount that snap back to the same ESX. This allows you to restore a single VM from 1 Datastor to another. You could also recover the entire datastore from Snap/Clone.

Take a look at the quick demo if you like. EMC also has a ton of whitepapers are RM/Vmware/EMC storage.

Let me know if you have any questions.