How many CPU license is required for SRM in our case ?

[TonyJK]

We are currently using 10 CPU license for ESX 3.5 Hosts at our HQ. We are going to deploy ESX Hosts at remote sites with 2 DELL PE2950 Server. Each server has 2 Quad-Core CPU. In other words, we will acquire another 4 CPU licence for ESX 3.5 Hosts for remote site.

We consider using Site Recovery Manager. So far as we know, the license for SRM is per CPU. We would like to know how many CPU licenses we need to purchase in our case ? Is it 4 ?

Regards

[weinstein5 · Accepted solution]

See Jay's responses for the full explanation. - Message was edited by: weinstein5

[TomHowarth]

I have moved this post to the SRM forum,

Tom Howarth

VMware Communities User Moderator

[Jay_Judkowitz]

Tony,

The answer is that it depends.

1) If you are protecting VMs from all hosts at the production site, you need 10 CPUs of licensing to protect from site A-->B

2) If you segregate your VMs such that, say only 6 CPUs of hosts are running protected VMs and 4 CPUs of hosts are running unprotected VMs, then you would only need 6 CPUs of licensing to protect from site A-->B.

3) Once you've determined how many CPUs to protect site A>B, you need to look at B>A. If you have VMs running at site B that are protected to A, then you would need to license up to 4 CPUs there. If, however, you only protect from A-->B, then you would not need any licenses for B since you only pay for protected hosts, not recovery hosts.

I hope this clarifies things for you.

Thanks,

Jay

[Jay_Judkowitz]

I should make one clarification. Please note that the SRM and ESX licenses are not calculated the same way.

• My answer was for SRM CPUs and you should follow that answer and not David's.

• David's answer is the correct for ESX CPUs.

[TonyJK]

Dear Jay,

Many thanks for your advice. We would like to protect A --> B only. In this way, we will need 10 CPU license for SRM.

Moreover, since the VM will migrate to another ESX Host by DRS, how can we set up a VM as protected ? For our site, we have 3 ESX Hosts - 2 of them with 4 CPU and the remaining one with 2. Is there any way to make sure that only 8 CPU contain protected VM ?

You also mention that there is difference between SRM and ESX host license. From my understanding, for ESX Host, a license is required per 2 CPU. Is it what you refer to ?

Thanks

[Jay_Judkowitz]

> Moreover, since the VM will migrate to another ESX Host by DRS, how can we set up a VM as protected ? For our site, we have 3 ESX Hosts - 2 of them with 4 CPU and the remaining one with 2. Is there any way to make sure that only 8 CPU contain protected VM ?

To do this, you would need to restrict 2 hosts to one cluster and one host to another. As you note, this would affect your DRS efficiency. For a cluster that small, I would suggest keeping it together and using 10 CPUs of SRM.

> You also mention that there is difference between SRM and ESX host license. From my understanding, for ESX Host, a license is required per 2 CPU. Is it what you refer to ?

What I mean here is that with SRM, you license what you protect, but with ESX, both sides need to be licensed. So, while you need 10 CPUs of SRM, you need 14 CPUs of ESX.

[TonyJK]

Dear Jay,

Thank you for your advice. We will use 10 CPU license for SRM.

Regards

[TonyJK]

Dear Tom,

A fellow has suggested me to remove the designation for marking Dave Weinstein's answer as Correct. This is because it is incorrect and will mislead others.

I have tried but am not able to do so. Would it be possible for you to remove the "Correct" desingation ?

Thanks