ddb.virtualHWversion in VMDK descriptor file

[vm2i]

Can anyone shed some light on theddb.virtualHWversion field within a VMs vmdk file ?

I assumed it define the version of the virtual hardware and would match the version defined in the VMX file. However -  if I create a VM at HW version 7,then both the version field in the VMX and the version in the VMDK are both set to 7. (good).

I then upgrade the hardware to version 10 but only the contents of the VMX file gets updated and the entry in the VMDK remains at 7.  Is this an issue ?

regards

[rachelsg]

Hi

Welcome to communities.

well explained -http://searchvmware.techtarget.com/tip/Understanding-the-files-that-make-up-a-VMware-virtual-machine.

[vm2i]

Thanks for the useful pointer. However my question is this one -

I have  a VM at HW version 7. I then upgrade the VMs hardware to version 10 but only the contents of the VMX file gets updated and the entry in the VMDK remains at 7.  Is this likely to cause any issues ?

[a_p_]

I can't tell you for sure. However, I think the version depends on whether new virtual disk features have been added, and to protect against possible incompatibilities. I've never had any issues with VM's which were upgraded from older versions, so it's more likely a protection against using a new virtual disk - e.g. SATA which was introduced with HW version 10 - in older ESXi versions. There's a KB with an example about increasing the version, where you can see that it may only depend on the virtual SCSI adapter rather used, than the flat (data) file format itself (http://kb.vmware.com/kb/1014720).

André

[vm2i]

thanks for the reply.

Just to make you aware this query came about whilst I was investigating Veeam Backups on our VM infrastructure. I noticed a number of VMs had VMDKs which could not be backed up using Veeam 'Hot Add' feature. I am still investigating but it seems that we had a number of VMs that had been deployed from a template and for some reason there was no entry in the VMDK descriptor file for ddb.virtualHWversion. It seems like Veeam is checking for this entry and if it isnt there it cant do hotadd... (or at least this is what my troubleshooting had found so far). So I started adding the ddb.virtualHWversion into the VMDK files and Veeam Hotadd then worked. It was during this investigation that I noticed a number of VMDK files with 'out of date HWversion info' but it seems that it may not affect anything (except for Veeam hotadd)

As far as Veeam is concerned, it seems that as long as there is an entry ddb.virtualHWversion in the VMDK then it can do Hotadd - regardless as to what the value is set to... I will raise this question with Veeam support.