Adding vRAM to OVA - TAC Supported?

[sachin050205]

We are in the process of adding Physical RAM to ESXi hosts. If we increase the vRAM available to UC applications 10.5 (Call Manager/UnityConnection), which is more than desccribed in OVA template, will it be Cisco TAC supported?

For example, if OVA template uses 4 GB RAM, and I increase the RAM to 8 GB. is it considered as supported configuration?

Thanks/

Sachin

[Deepak Rawat]

It is not supported to increase RAM or any other settings other than what comes with the deployment of OVA. Check below information which is available at:

http://docwiki.cisco.com/wiki/Unified_Communications_VMware_Requirements#Virtual_Machine_Templates_.28OVA_files.29

Virtual Machine Templates (OVA files)

NOTE: support varies by app and version. Before reading the best practices below, verify support at Supported Editions and Features of VMware vSphere ESXi, VMware vCenter and VMware vSphere Client.

See www.dmtf.org for details on the Open Virtualization Format, which describes an OVF Package (a directory of files describing a virtual machine's configuration) and an OVA Package (single tar file containing an OVF Package).

“Template” in this context refers to an OVA file that defines the virtual server (but not the “workload”, i.e. the UC OS and application). Each virtualized UC product provides a set of predefined virtual machine templates (as OVA files) for supported Virtual Machine (VM) configurations. Customers must download and use these OVA template files for initial install, as they cover items such as supported capacity levels and any required OS/VM/SAN “alignment”. OVAs configured differently than the predefined templates are not supported at this time. To download the OVA files, refer to the Unified Communications Virtualization sizing guidelines.

Regards

Deepak

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[Brandon Buffin]

Yes, this is supported as long as the change does not result in an unsupported configuration and does not remove resources (i.e. decreasing the amount of RAM). Also, per the doc below the VM will need to be shut down to add RAM (hot add is not supported).

http://docwiki.cisco.com/wiki/Unified_Communications_VMware_Requirements#Resize_Virtual_Machine

Brandon

[sachin050205]

Thanks for your response Brandon. Thats what my understanding is.

The OVA template gives you recommended minimum requirements for UC applications (in this case). For example, if Hard Disk space for a perticular OVA is 80 GB, if I put a 90GB hard Disk, how its not supported. Similarly, if RAM specified by OVA is 4GB and If I put a 8 GB RAM, it should be (technically) supported.

FYI, the resources are being increased here (instead of descreasing RAM or Hard disk).

[Deepak Rawat]

Brandon, sorry to say but that section of the docwiki which you are referring to is only applicable 

"When a particualr VM had not been configured from OVA template and is running on less resources than what is defined in OVA template"

Anything in terms of increasing or decreasing the resources for a VM apart from what you get by deploying an OVA template is not supported and should not be done.

Regards

Deepak

[sachin050205]

Deepak,

Thanks for your responses.

From the link in your first response, in RESIZE Vitrual Machine section-  it says:

• Adding vRAM is supported but requires VM to be shutdown first.

Not sure, if it has another caveat to it.

Warm Regards

Sachin

[Deepak Rawat]

I already have replied on Brandon's post when is it applicable to modify RAM, only if the specs are less than what they should be as per OVA.

Modifying the specs be it increase or decrease against the OVA specs is not supported and should not be done if you want to stay within the supported guidelines from TAC perspective.

Regards

Deepak

[Jaime Valencia]

No, that's wrong, IT IS SUPPORTED to increase the VM resources when it comes to HDD, vRAM vCPU. As Brandon pointed out, and explained in the virtualization wiki

The caveat, is that for vRAM and vCPU, you can only increase the resources, and you would need to match one of the OVAs for the product. You cannot create your own specs, they would need to match one of the OVAs we provide for the products.

For example, and I'm just making this scenario to get the point across

1K users uses 1vCPU and 4 GB of vRAM

2.5K users uses 2 vCPU and 6 GB of vRAM

If you want to change the specs from 1K to 2.5K, you simply need to change the specs from the VM, and IT IS SUPPORTED.

On the other hand, if you want to have that CUCM with, I don't know, 6 vCPUs and 16 vRAM because you think that is better, that would NOT be supported, as those specs do not match any of the virtualization wiki.

As for HDD, that is supported, the applications now have the ability to increase the common partition size as required if you wish to have more data. What you CANNOT do in regards to HDD, is to add/remove HDDs, NOT THE SAME as increasing the size of the ones that come with the OVA specs. That should only be used on special circumstances, not an everyday procedure (for example, for upgrades.)

[sachin050205]

Thanks Jaime. 

Just to recap, as per your response, if I am moving from one OVA (say 1k Users) to higer resource level OVA (say 2.5k Users), then increasing resources (to match higher level OVA specs) is supported.

But, within the same OVA specs (say 5k users), if I try to increase vRAM from 4GB (OVA specs) to 8 GB (4 GB over OVA specs), its NOT supported.

[Jaime Valencia · Accepted solution]

Correct, you cannot create your own custom specs because you want more resources. Any change you make, you need to fit within the OVAs specs outlined here

http://docwiki.cisco.com/wiki/Virtualization_for_Cisco_Unified_Communications_Manager_(CUCM)

Anything that does not match the vCPU and vRAM outlined there, will not be supported.

[Deepak Rawat · Accepted solution]

Your understanding is absolutely correct Sachin. You can increase the resources to match higher level OVA specs and that is supported without the need of rebuilding the VM again. But you cannot increase or decrease the resources for a particular OVA specs, whatever resources an OVA gives you, you will need to use them only.

Regards

Deepak

[sachin050205]

Thanks Again Deepak and Jaime.