HA/Replication or Stretched Cluster

[auricemetrocomm]

Need your guys' guidance on a DA/DR project I'm working on. From what I understand, there are 3 possible ways to create an offsite backup for VMware: Replication/HA, Stretched Cluster, and Site Recovery Manager (too expensive for us). Any advice on which one is better for the situation described below?

2 sites with 3 hosts at each location: (2) R630's and (1) PowerVault SAN)

- Each site has identical hardware/software/VMs, etc.

- We don't have a lot of requirements, other than the recovery site needs to come up within a few minutes of the primary site going down. Saving money trumps ease of use & recovery time

- We have a redundant 1GB/s L2 (possible 10 gig if needed) connection between both sites

-If I went with Replication/HA, would I need another vCenter at site 2? If not, would I just use the vSphere client to manage the VMs at the recovery site temporarily?

-Will I need to buy & install additional ESXi on the recovery site hosts for both Replication/HA and Stretched Cluster methods?

-Which one is easier to initially setup?

-Will I need vSAN?

-And lastly, do I need to buy an OS (Win Server 2016) for each logical processor to run ESXi on?

Thanks guys

[ITaaP]

Have you looked at a third party solution such as Zerto or Veeam? If you need a low RPO, then Zerto is probably your best option. I replicate cross country with sub 1 minute RPO.

[vbrowncoat · Accepted solution]

The lowest cost option would be vSphere Replication. This is included with vSphere Essentials Plus licensing and higher. Keep in mind that recovery will be a manual process (recovering each VM individually) and there won't be any way to non-disruptively test your recovery. You would need to purchase a vCenter for the recovery site as VR is dependent on VC so you wouldn't want to be using a single VC.

I'm not sure what you mean by Replication/HA as an option. In the context of vSphere Replication and HA are two very different solutions. vSphere Replication (VR) is a per VM, host level replication solution. HA is a cluster level solution primarily for recovering VMs after a host failure, unless used with stretched storage and vMSC it is not a DR solution. The two solutions do interoperate (a HA protected VM can be replicated).

You would need to license your hosts at the recovery site for this to work as the VR VMs and the vCenter will be running at the recovery site.

I don't believe that stretched cluster will be an option for you as I don't believe it is something that PowerVault supports. There is also the question of latency requirements (5ms RTT max) and cost (stretched solutions are usually a lot more expensive - other than vSAN). If you want a vSAN stretched cluster for this environment (assuming you meet the requirements) you would need a vSAN license, otherwise not.

Not sure what exactly you are asking about regarding windows licensing. You are possibly better off asking MS or posting it to a VMTN forum that discusses those types of questions.

I also want to point out that these are not your only options. If you aren't concerned about manual effort or recovery time you could always backup your VMs and replicate your backups to the recovery site. Depending on the backup solution this could require a minimum number of vSphere licenses (assuming they can be moved from protection to recovery when needed) and no VC license for the DR site. The RPO and RTO for this option would correspondingly be much higher than the other options.

[auricemetrocomm]

Thanks for the detailed answer. If I have to purchase a separate vCenter to use VReplication, wouldn't I be better off just buying the SRM license? It's fairly similar in price I believe.

[vbrowncoat]

SRM requires a vCenter at both sites as well. Really, from a DR perspective, if you use vCenter at one site now, you will want a vCenter at your recovery site as well. It usually doesn't make sense to make vCenter a part of the failover so a second vCenter will often make sense.

At the end of the day though it really comes down to your requirements and constraints.

[auricemetrocomm]

So it's not possible to use the vSphere client on the recovery site to avoid another vCenter license? These VMs are very low maintenance; once they're running we won't need access.

[vbrowncoat]

Like I said previously, VR and SRM require a vCenter at the recovery site. If you don't want a vCenter then more than likely your option would be looking at a backup solution. You could also look at a solution like Veeam or RecoverPoint For VMs. I don't know if either or both of them require a vCenter at the recovery site.