Problem
An attempt made using NBU to backup VM that vmdk file more than 300GB on datastore created with block size of 1mb. •Creating a snapshot for a virtual machine fails •You receive this error: File is larger than the maximum size supported by datastore •In the /var/log/vmware/hostd.log file you see this error: Snapshot guest failed: The file is too big for the filesystem.
Error Message
File is larger than the maximum size supported by datastore '
Cause
This occurs if the datastore created with block size of 1mb and VMDK size grows more than 256 GB . Snapshot creation have limitation of max size limit of 256 GB
Solution
The maximum file size corresponding to block sizes on a datastore are:
Block Size: Maximum File Size (Snapshot)
- 1 MB: 256 GB
- 2 MB: 512 GB
- 4 MB: 1024 GB
- 8 MB: 2048 GB
If you experience this error even after confirming that the snapshot files can fit on the datastore, proceed to Calculating the overhead required by snapshot files in this article. To resolve this issue you can either change the location of the virtual machine configuration files or change the workingDir to a datastore with enough block size. workingDir is the location where the snapshots are created, By default, workingDir contains the .vmx file).
Applies To
NBU 7.0 Vsphere 4.0