Creating a snapshot for a virtual machine fails with the error: File is larger than maximum file size supported
VMware ESX/ESXi 4.0 and Later using VMFS3
Symptoms / Description
When creating a snapshot for the virtual machine, you experience these symptoms:
- In the vSphere Client, you see this error:
File is larger than the maximum size supported by datastore
- In the hostd log file, you see this error:
Snapshot guest failed: The file is too big for the filesystem.
- In the vmware.log file of the virtual machine, you see an error similar to:
vmx| FILE: File_VMFSSupportsFileSize: Requested file size ( 554051831808) larger than maximum supported filesystem file size (274877906944)
vmx| DiskLibCreateCustom: if your disk is on VMFS, you may consider increasing the block size.
vmx| DISKLIB-LIB : Failed to create link: The destination file system does not support large files (12)
vmx| SNAPSHOT: BranchDisk: Failed to create child disk ' /vmfs/volumes/uuid/vmname/vmname-000001.vmdk' : The destination file system does not support large files (12)
vmx| SNAPSHOT: SnapshotBranch failed: The destination file system does not support large files (5).
vmx| [msg.checkpoint.save.fail2.std3] Error encountered while saving snapshot.
vmx| The destination file system does not support large files.
Alternate Solution for 7.2 Systems and Later
- For Unitrends Software Version 7.2 and later, VMware Disk Exclusions are supported.
- On the vSphere Client, make the 2TB disk/s of type 'Independent Disk'. This can be done by the following steps:
a. On the vSphere Client, right click the Virtual Machine whose Backups are failing
b. Click on 'Edit Settings'
c. Various Hardware of that Virtual Machine Will be seen. Click on the 'Hard disk' which is of size 2TB
d. Check 'Independent'
e. Click 'OK'
- Now, this disk will automatically be excluded from the Backup and the Backups of this Virtual Machine will be successful.
Note: With VMFS5, in ESXi 5.5 and later, no overhead calculations are required for virtual disks (VMDKs) greater than 2 TB in size, because during creation the system automatically accounts for the space required to snapshot the disk. With VMFS6, no overhead calculations are required for virtual disks (VMDKs) regardless of the size.
This failure occurs when the snapshot file at its maximum size would be unable to fit into a datastore. With VMWare versions 4.0-5.1 and using VMFS3 , ESX and ESXi compare the maximum size of a snapshot redolog file with the maximum size of files on the datastore. The redolog file may not work correctly once it reaches the maximum size of the datastore. If the file could grow beyond the maximum size, ESX cancels the Create Snapshot operation and displays this error instead.
Refer the VMware KB below for more information.