Does SRM require the same version of vSphere at both sites?

[jwall04]

We are needing to implement SRM quickly, I know it's not the way to do it but this is a decision I am not charged with. We are going to be using SRM 5.1.  I haven't read the SRM documentation totally yet, but I'm hoping someone can answer me this:

Do we need to be running the same version of vSphere at both sites?

Site A (Production):

- vSphere 4.1 (update nothing) Enterprise - because our hardware is NOTon the compatibilty list for anything newer

- vCenter 5.1 - We'll be upgrading our current vCenter Server 4.1 server to 5.1

Site B (DR):

- vSphere 4.1 U2 (or newer) Enterprise - This hardware is NOT identical to that of Site A but is compatible with 4.1 U2 thru 5.1

- vCenter Server 5.1

Do we have a workable solution here?

Thanks for the help.

[vmroyale]

Check out this recent discussion on this.

[kwerneburg]

Your scenario should be fine, presuming you're using array based replication.  SRM doesn't require the same version of vSphere.

It does require that your vCenter server be at the same version, which you have, so it will be okay.  Since you'll be running VC 5.1 you'll also need to run SRM 5.1 (these need to match).

Hardware doesn't matter at all as you map things like resources pools and port groups in your inventory mapping rather than clusters or hardware.

In fact I'd say you're doing well to fail over from a 'lower' version to a 'higher' version, since that way you don't have to worry about things like unsupported VMware Tools or VM hardware.

[jwall04]

@kwerneburg, yes we plan on installing SRM 5.1 at both sites.  For our DR site we've bought vSphere 5.1 Enterprise and will downgrade the license to whatever version we need to run at the DR site, and we are NOT using array based replication, but planning to use the vSphere Replication (if I have that term correct?) included in vSphere 5.1, which we should be licensed for even after we've downgraded the license if I understand this all correctly.

Does this all still sound doable?

If failing over from a lower version to higher version puts us in a better position, what happens when we have to fail back, say after a test migration?

[mal_michael]

Hi,

vSphere Replication is done by ESX. So, for this to work you need ESXi 5.0 or 5.1.

Michael.

[kwerneburg]

Failover and failback will be fine as long as you don't update the tools and HW while it's failed over.

But VR requires ESXi 5.x...

[jwall04]

aHmmm, ok we do not have a storage based replication option, our SANs do not support it.  So to be clear, does this mean we cannot use vSphere Replication?  Do I have this correct, SRM requires either a third party storage based replication method or the VMware created vSphere Replication, is this right?

We spoke to a VMware engineer the other day and the way it was explained to me was that since we've purchased vSphere 5.1 Enterprise we have access to vSphere Replication, even though we were going to downgrade that license to 4.1.  I was under the impression it would be a license key that would appear in our licensing portal that we'd use to "turn" this on.  The more I think about it now, the less it sounds correct.

But, if we use vSphere 5.1 at our DR site, this should all wor?  Is it wise for use to proceed with the plan of updating our production site vCenter Server 4.1 to 5.1, installing SRM 5.1 and installing vSphere 5.1, vCenter Server 5.1, SRM 5.1 at our DR site?  I should reiterate again that this project has not been planned out properly...

[kwerneburg · Accepted solution]

You are correct that SRM requires either 3rd party replication or VMware vSphere Replication (or you can use both together).  SRM itself doesn't replicate anything, it orchestrates and manages the recovery of VMs protected by those other mechanisms.

If you don't have the option of array replication then you must use vSphere Replication.

VR, however, is a function of the ESXi kernel that appeared in 5.0.  It's inherently a part of the hypervisor itself, so it needs a 5.x or higher host to use it, it's not a licensing issue at all.

In order to use VR you'll need hosts at both sites to be using 5.x - the source site needs 5.x to use the agent/filter in the kernel that produces the replica data.

My *personal* take on this is you'd be best served to get up to VC 5.1 at both sites, then upgrade your hosts to 5.1, then deploy the virtual appliances for VR (used to manage the replication and register the service with VC), then protect some VMs so you can get accustomed to the VR behaviour, then put SRM on top (5.1 at both sites) and start building protection groups and recovery plans and such.

[jwall04]

I'm sorry I am having such a hard time with this...

To be clear, upgrading our hosts at our primary site to 5.1 is not possible, they're not on the HCL, so we have to stick with 4.1 U0 there.

[kwerneburg]

Then I suspect you're in trouble... if your arrays can't do replication then that leaves VR as your only option, and if your hosts can't move to 5.x then you can't use VR either.

To use SRM you'll need one or the other - arrays that replicate, or hosts that support 5.x.

[jwall04]

Or, use SRM pre 5.0 which includes VR?

If so the issue then becomes the cost because there was only one pre 5.0 version of SRM available, whereas now we can buy the Standard version and limit ourselves to 25 vms.

[kwerneburg]

Pre-5.0 there is no VR.

[jwall04]

Thanks, for the info.  SRM and VR look slick but we won't able to use them yet since we are not on ESXi 5