vSphere Replication is replicating huge data though there are no changes occurring on the VM

Products

• VMware Live Recovery
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• vSphere Replication is replicating huge data though there are no changes occurring on the VM.
• VM is Windows.
• VM is a RHEL or other Linux.

Environment

VMware vSphere Replication 8.x
VMware vSphere Replication 6.0.x
VMware vSphere Replication 6.1.x
VMware vSphere Replication 6.5.x

Cause

This issue is caused by a GuestOS sent unmap command.

Resolution

To disable in RHEL or other Linux please reference your OS documentation or contact the Linux Distro provider.

To disable Unmap in the Windows Guest OS:

 

Using a Windows CMD window on the Host, run the command:

 

fsutil behavior set DisableDeleteNotify 1

 

To re-enable the feature, use the following command:

 

fsutil behavior set DisableDeleteNotify 0

 

To verify the current setting, use the following command:

 

fsutil behavior query DisableDeleteNotify

 

• DisableDeleteNotify=0 - indicates the Trim and Unmap feature is on (enabled)
• DisableDeleteNotify=1 - indicates the Trim and Unmap feature is off (disabled)

Note: You can check the ESXi host setting for Unmap. For more information, see Disabling VAAI Thin Provisioning Block Space Reclamation (UNMAP) in ESXi 5.0 (2007427).

 

Additional Information

Applying storage policy to disk files, the disk consumed space is bigger again. It is storage policy configuration.  Because of the storage policy, the used space is larger than original size. It is expected. For example, if one file is 10GB, after applying RAID 1 policy, it will be about 20GB.