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Druva Documentation

Impact of Thick and Thin Provisioned VMware Disk on the current source

Describes the data backup and restore size using Thick or Think disk for VMware backups.

Overview

This article provides a clear understanding of the data backup and restore size using Thick or Think disk for VMware backups.

Assumption: The example in this article has 1 VMDK for each virtual machine.

Impact on backup

The following table lists the backup size consumed by the storage for Thick and Thin Disk.

Disk Provisioning = Thick (Lazy / Eager Zero) Disk provisioning = Thin
VM disk size = 150 GB VM disk size = 150 GB
Total User data on Disk = 20 GB Total User data on Disk = 7.42 GB
Current Source shows = 150 GB Current Source shows = 7.42 GB
Source + Changes = 150 GB Source + Changes = 7.42 GB

The above table indicates the following:

  • When the VM disk is Thick provisioned, Druva shows the size of the Disk. (This may vary if the disk size is increased or reduced from VM settings.)

    DataTrend.pngRestoreData1.png
  • When the VM disk is Thin provisioned, Druva shows the actual data as current source present on disk and not the complete disk size.

    DataTrend2.png

Note: If the datastore type is any of "NFS", "NFS41" or "NFS42" file system, then the Current Source size is equal to VM disk size.

If the datastore type is other than the NFS file system and the disk type is a thin disk, then the source size for the first backup is equal to the total size returned by QueryChangedDiskAreas API for all the vmdk attached to the VM.

Impact on restore

For restore:

  • Both the Thick and Think disks show the actual size of the disk in the restore window.

    RestoreData1.png
  • The data restore size in the Thin disk is the data that was backed up. (For example, if 7.42 GB/150 GB was backed up, then the estimated size is 150 GB, but the restore size is 7.42 GB only.)

    The estimation phase shows the actual disk size for the Thin disk.

    RestoreData2.png

    The actual restore job log shows 7.42 GB only.

    RestoreData3.png

Related article

Restore VMware virtual machine to an alternate location