Editing VM Group Settings for VMware

For an existing VM group, you can modify options that affect backups.

VMware Transport Considerations

Licensing: In vSphere 5.0, the SCSI HotAdd feature is enabled only for vSphere editions Enterprise and higher, which have Hot Add licensing enabled. No separate Hot Add license is available for purchase as an add-on. In vSphere 4.1, Hot Add was also enabled in the Advanced edition. Customers with vSphere Essentials or Standard editions are not able to perform proxy-based backup, which relies on SCSI HotAdd. Those customers must use alternate transport modes.

SCSI Controllers: HotAdd relies on the SCSI protocol. With VDDK 6.5 or later, VMware recommends the paravirtual SCSI (PVSCSI) controller. (For more information, see Virtual Disk Development Kit Release Notes.) For older VDDK versions, use the LSI SCSI controller. HotAdd does not support IDE disks.


  1. From the navigation pane, click Solutions > Virtualization > Hypervisors.

    The Hypervisors page appears.

  2. Click the name of the hypervisor that hosts the virtual machines.

    The hypervisor details page appears. The VM groups area displays summary information for any existing VM groups.

  3. Click the name of a VM group.

    The VM group details page appears.

  4. Snap mount esx host: For VM groups that have a snap plan assigned, click Edit and then select an ESX server that can be used to mount snapshots for IntelliSnap backups.

    The Settings area shows settings that are used to back up the virtual machines in the VM group.

  5. In the Settings area, click Edit.
  6. In the Edit options dialog box, provide the following information:
    • Use changed block tracking: Select this option to use changed block tracking (CBT) for backups.

      With CBT, backups only write blocks that have changed since the previous backup. For virtual machines where there is a known issue with CBT, you can turn off CBT to run backups using the cyclic redundancy check (CRC) method instead.

    • No. of readers: Set the number of readers to control how many parallel read operations can be launched during backups.
    • Virtual machine backup type: Select one of the following options:
      • File system and application consistent: An application consistent backup quiesces the file system and applications while performing the backup.
      • Crash consistent: A crash consistent backup takes a point-in-time snapshot of virtual machine data without quiescing.
    • Transport mode for VMware: Select one of the following options:
      • Auto: The transport mode is selected automatically based on the backup environment:

        If the datastore is accessible to a physical proxy, SAN is used.

        If the datastore is accessible to the ESX server for a virtual proxy, HotAdd is used.

        Otherwise, NBD is used.

      • SAN: For directly connected storage using Fibre Channel (FC) or Internet SCCI (iSCSI) protocols. The Virtual Server Agent must have access to the datastore LUNs (logical drives) that provide storage for virtual machine disks. Data is read directly from the storage where virtual machines reside, without going through the ESX host or transferring data over the local area network (LAN). The ESX host is contacted only to coordinate access to the LUN. SAN transport mode cannot be used if the proxy computer is a virtual machine.
      • Hot Add: The Virtual Server Agent is installed on a virtual machine residing on an ESX server. In HotAdd mode, the data volumes containing the virtual machines to be backed up are automatically mounted to the proxy, so they can be accessed by the proxy as a local disk. The ESX host the proxy is running on must have access to all datastores for the virtual machine. If the virtual machine and the proxy are not on the same host, all datastores must be shared between the hosts.
      • NBD: Data is transferred using the TCP/IP connection between the ESX server and the proxy computer. The local area network (LAN) can be the production network or a dedicated backup network.
      • NBD SSL: Similar to NBD mode, but data transfer between the proxy computer and the ESX server is encrypted. Encryption should be used for sensitive information, even within a private network.
    • Datastore freespace check: Select this option to ensure that there is sufficient free space on the datastore before performing the backup.
    • Datastore freespace required: Type the percentage of free space that should be available on the datastore before performing the backup.
    • Collect file details: Select this option to collect file and folder information during streaming backups or when creating a backup copy from IntelliSnap backups. Use this option when creating a copy for tape storage, because file and folder information is required when recovering files from tape.
    • Collect file details for snapshot copy: Select this option to collect file and folder information when creating a snapshot copy from IntelliSnap backups. Use this option when creating a copy for tape storage, because file and folder information is required when recovering files from tape.

      Note: Collecting file details increases the time required to perform backups, and is not required to enable recovery of guest files and folders.

  7. Click Save.

Last modified: 12/3/2018 10:58:33 PM