File <unspecified filename> is larger than the maximum size supported by datastore '<unspecified datastore>'

[spoonwzd]

I know this issue has been mentioned a lot in the forums, but the answers are always to make sure that your block sizes are set to 8MB - mine already are. Let me explain:

I have a VM with a large amount of storage attached - something along the lines of 10x 1.99TB drives. All VMDK's sit on 8MB block size VMFS partitions, including the VM configuration (swapfile location).

Whenever I try and snapshot the VM I see the "File <unspecified filename> is larger than the maximum size supported by datastore '<unspecified datastore>". All other VMs snapshot fine, but no other VM has a similar amount of storage as the problematic VM.

I have now moved the VM's config files to a new 1.91TB VMFS 5 partition, but the snapshot error still occurs. Most of the drives are sat on VMFS 3.33 or 3.46. It will take me a while to move them all to VMFS 5 to see if that fixes the problem.

vmware.log for the VM reports:

2011-10-09T09:55:55.328Z| vcpu-0|  DiskLibCreateCustom: Unsupported disk capacity or disk capacity (2186928627712 bytes) is too large for vmfs file size.
2011-10-09T09:55:55.328Z| vcpu-0| DISKLIB-LIB   : Failed to create link: The destination file system does not support large files (12)
2011-10-09T09:55:55.328Z| vcpu-0| SNAPSHOT: SnapshotBranchDisk: Failed to branch disk: '/vmfs/volumes/4dc30ba3-b13c5026-92d8-d485643a1de4/spoon-app/spoon-app_2.vmdk' -> '/vmfs/volumes/4dc30ba3-b13c5026-92d8-d485643a1de4/spoon-app/spoon-app_2-000001.vmdk' : The destination file system does not support large files (12)

My VMDKs and volumes are smaller than 2032GB. I'm not understanding why this is being problematic.

Anyone have any ideas?

[a_p_]

According to the file size in the log file, the vmdk is ~2,036GB which is too large to be able to create a snapshot (see http://kb.vmware.com/kb/1012384)

I have now moved the VM's config files to a new 1.91TB VMFS 5 partition...

In ESXi5, snapshots are created in their partent's datastore by default. If you want the snapshots to be created in the VM's base folder you'll have to add

snapshot.redoNotWithParent = "TRUE"

to the VM's configuration.

André

[spoonwzd]

Thanks for your response Andre.

spoon-app_2.vmdk

This drive is 1.99TB in size according to the vSphere client - I deliberately set it lower to make sure it was under 2TB!

I think I understand where I've gone wrong in my sizing calculations - thanks for the help!

[spoonwzd]

Oh, why now that I've moved to ESXi 5 which supports larger than 2TB is this still an issue?

[a_p_ · Accepted solution]

Although ESXi 5 supports larger LUNs as well as physical raw devices (up to 64 TB), the maximum size for a virtual disk has not changed yet.

André