Include.vmresetcbt

Use the include.vmresetcbt to reset the change block tracking (CBT) mechanism for a virtual machine (VM) or a group of VMs.

If you need to reset the change block tracking on a VM or set of VMs, use this option to manage which VMs are reset so that all VMs are not reset at the same time. Managing which VM's change block tracking is reset is important because resetting change block tracking for a VM forces a full backup of that VM.

While there can be different reasons for resetting change block tracking, one reason is if you suspect that a snapshot existed at the time change block tracking was initially enabled for a VM. Enabling change block tracking on Data Protection for VMware means to complete an incremental-forever backup operation.

Enabling change block tracking when a snapshot exists is a known issue with VMware change block tracking. This known issue might cause incomplete or invalid change blocks information to be returned during a backup operation. To resolve this issue, you must remove all existing snapshots for a VM, and reset change block tracking for the VM before you run an incremental-forever backup operation.

Subsequent incremental backups will track the blocks that changed since the last backup operation.

Specify this option only for one-time use for a VM or group of VMs. After you reset change block tracking for a VM by running an incremental-forever backup operation, remove the include.vmresetcbt option from the options file. Use this option only if change block tracking needs to be reset for a VM, such as when one or more third-party or manual snapshots exist on a VM.

Data mover This feature is available only if the client operates as a data mover for IBM Storage Protect for Virtual Environments: Data Protection for VMware.

Supported Clients

This option can be used with supported Windows and Linux® clients.

Options file

Place this option in the client options file (dsm.opt).

Syntax

Parameters

vmname

Specifies the name of a VM for which you want to reset change block tracking. The name is the VM display name. This parameter is required.

Only one VM can be specified on each include.vm statement. However, you can specify as many include.vmresetcbt statements as needed.

You can include wildcards in the VM name. An asterisk (*) matches any character string. A question mark (?) matches a single character. If the VM name contains a space character, enclose the name in double quotation marks (").

Tip: There is no equivalent option that excludes VMs from having change block tracking reset. Therefore, you must specify more granular VM names when you reset change block tracking for a group of VMs. For example, you cannot specify an include.vmresetcbt statement to include all VMs that begin with "EXEC" and an exclude statement to exclude the VMs that begin with "EXECTEST".

Examples

Task 1

Reset change block tracking on all VMs with names that begin with "Prod" followed by any single character:

INCLUDE.VMRESETCBT Prod?

Task 2

Reset change block tracking on all VMs with names that begin with any two characters, followed by "Prod", followed by zero or more characters:

INCLUDE.VMR ??Prod*

Task 3

Reset change block tracking on all VMs with names that begin with one or more characters, and end with "Prod":

INCLUDE.VMRESETCBT ?*Prod

INCLUDE.VMRESETCBT *?Prod

Task 4

Reset change block tracking on all VMs with names that begin with "Corporate Mail", followed by zero or more characters:

include.vmr "Corporate Mail*"

Task 5

Reset change block tracking on all VMs:

include.vmresetcbt *