Introducing Arcserve Backup Agents and Options › Using Agents › Agent for Virtual Machines › Installing and Configuring the Agent › Post Installation Tasks › VMware vSphere Integration Post Installation Tasks › Specify a Backup Approach

Specify a Backup Approach

The agent lets you specify one of the following approaches to protect VM backup data:

VMware vSphere Web Services SDK and VMware VDDK--Lets you protect the following implementations:

• ESX Server 3.5 and above when managed by vCenter Server 4.0 and above
• VMware Virtual Center 2.5 and above up to vCenter Server 5.1 managing ESX Server 3.5 and above up to ESX Server 5.1.

VMware vSphere Web Services SDK and VMware VDDK Approach

When using the VMware vSphere Web Services SDK and VMware VDDK approach, consider the following:

• With this approach specified, Arcserve Backup uses VDDK to process raw (full VM) backups and raw (full VM) backups with the Allow file level restore option specified when VDDK is installed on the backup proxy system. However, by default, the agent always uses VDDK for all backups and all versions of ESX Server.
• Arcserve Backup backs up only the active blocks relating to the full backup phase of raw (full VM) backups (with and without the allow file level restore option specified), and mixed mode backups with the allow file level restore option specified.

  If the virtual disks are provisioned as Lazy zeroed thick or thin disks, the agent creates backup sessions that are approximately the same size as the used disk space on the VM.

  Arcserve Backup does not support the active block analysis approach on virtual machines that contain virtual raw device mapping (RDM) disks. However, if Arcserve Backup detects virtual RDM disks, you can submit full backups of the virtual RDM disks and recover the disks as normal thick disks.

  Note: Although active block backup jobs complete successfully, one of the following messages can appear in the Activity Log after the jobs run:

  • AW0720:Failed to create the disk bitmap for the disk, "Full disk including unused blocks will be backed up".
  • AW0589:Failed to enable changed block tracking for the virtual machine, "Full disk including unused blocks will be backed up".

  To correct the condition that generated messages AW0720 and AW0589, reset changed block tracking. For more information, see Failed to Create Disk Bitmap Errors Occur During Backups.

Be aware of the following limitations:

• Due to a VMware limitation, the agent does not support backing up raw device mapping (RDM) in physical compatible mode.
• The first time you back up virtual machines using this approach (active block backup), verify there are no snapshots on the virtual machines. For all subsequent backups, there can be one or more snapshots on the VMs.
• Arcserve Backup performs active block backups on virtual machines running on VMware hardware version 7 and the following VMware platforms:
  • ESX Server 4.0 or later
  • vCenter Server 4.0 or later
• Arcserve Backup performs active block backups on virtual machines running on VMware hardware version 8 and the following VMware platforms:
  • ESX Server 5.1
  • vCenter Server 5.1

• Backups store the snapshot in the mount directory specified using ARCserve VMware Configuration Tool.
• Arcserve Backup uses VDDK to recover data when the VM data is backed up using VDDK.

  Note: VMware converter is not required to restore virtual machine data that was backed up using VDDK.

• The backup process creates a file named vmconfig.dat in binary format that contains the VM configuration details.

  Note: You should not attempt to modify vmconfig.dat.

• The backup process does not create or update catalog files.
• The mount point directory does not display files for the mounted volume. This behavior occurs because VDDK does not mount volumes to a directory or map volumes to a drive letter.
• The backup process creates disk files with a zero file size in the mount directory for raw (full VM) backups and raw (full VM) backups with the Allow file level restore option specified.

  Note: You should not attempt to modify the disk files.