Back up a VMware ESX Server 3.x Virtual Machine

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Overview

• Backups from a VCB Proxy Server on a SAN using VMware Consolidated Backup
• Backups from the ESX Server Service Console
• Backups from the Virtual Machine

Overview

The data that resides on the virtual machines for VMware ESX Server can be backed up using an appropriate iDataAgent, in a variety of ways; this data can be for different platforms (e.g., Unix, Windows, NetWare, etc.) and can be backed up either using VMware Consolidated Backup and the Windows File System iDataAgent or ProxyHost iDataAgent on a VCB Proxy Server, or from the Service Console using the Linux File System iDataAgent. Backing up VMware virtual machines requires that the appropriate iDataAgent(s) be installed and that you follow the instructions provided, to create and apply the Pre-Scan and Post-Backup scripts needed to snapshot the virtual machines. Detailed information on system and environment requirements for VMware Consolidated Backup can be obtained from the Virtual Machine Backup Guide at the VMware web site.

VMware ESX Server Virtual Machine data can be backed up in the following ways:

• From a VCB Proxy Server on a SAN using VMware Consolidated Backup:
  • File Backup using the ProxyHost iDataAgent
  • File Backup using the Windows File System iDataAgent
  • Full Image Backup using the Windows File System iDataAgent
• From the ESX Server Service Console:
  • Full Image Backup using the Linux File System iDataAgent

  For VMware ESX 3i, only VMware Consolidated Backups are supported.

Backups from a VCB Proxy Server on a SAN using VMware Consolidated Backup

VMware Consolidated Backup (VCB) provides a set of drivers and scripts that enable LAN-free backup of Virtual Machines. A File backup can be performed for Virtual Machines running Windows, while a Full Image backup can be performed for Virtual Machines running any operating system. These backups are performed from a VCB Proxy Server running Microsoft Windows 2003, using pre-scan and post-backup scripts to perform a Virtual Machine snapshot and facilitate the backup from the VCB Proxy Server directly on the SAN. The backup client then backs up the contents of the Virtual Machine. Finally, the post-backup script unmounts the snapshot and takes the virtual disk out of snapshot mode.

When performing a File backup from the VCB Proxy Server, the following occurs:

• The PreScan batch file triggers vcbMounter to:
  • quiesce NTFS on the Virtual Machine
  • create a snapshot of the Virtual Machine
  • mount the Virtual Machine disk image from the SAN to the VCB Proxy Server
• The iDataAgent on the VCB Proxy Server backs up the files in the disk image
• The PostBackup batch file triggers vcbMounter to:
  • unmount and delete the disk image
  • delete the snapshot of the Virtual Machine

When performing a Full Image backup from the VCB Proxy Server, the following occurs:

• The PreScan batch file triggers vcbMounter to:
  • create a snapshot of the Virtual Machine
  • copy a disk image of the Virtual Machine across the SAN to the VCB Proxy Server
  • delete the snapshot of the Virtual Machine
• The iDataAgent on the VCB Proxy Server backs up the full disk image file(s)
• An optional PostBackup batch file can be used to delete the disk image(s)

Benefits

• Backups are performed on the VCB Proxy Server, eliminating the load on the ESX Server computer.
• No need to power down Virtual Machines as a snapshot-based backup is performed.
• Can be used in conjunction with ProxyHost iDataAgent (file backup only) for enhanced browse and restore functionality, showing original drive letter and path on the Virtual Machine, when browsing data for a restore.
• Full Image backup saves all the configuration files necessary for rapid disaster recovery of a Virtual Machine in case of catastrophic failure, and is supported for any Virtual Machine operating system.
• Full Image backups can be performed for all guest operating systems.
• For virtual machines running Microsoft Windows operating systems, full, incremental, and differential file backups allow recovery of individual files and folders.
• Eliminates LAN traffic through Fibre Channel SAN (Storage Area Network) usage.
• For file backups, when Windows is the guest operating system, enhanced operability for browse and restore is available by optionally installing the Window File System and ProxyHost iDataAgents on the Virtual Machine, since ProxyHost preserves the original mapping of files, folders, volumes letters, etc., in the backup.

Considerations

• Requires additional computer(s) for VCB proxy server(s).
• Requires a SAN.
• File backup supported only for Virtual Machines running Windows as the guest operating system.
• Full Image backup files are not remotely mounted via the SAN, rather are created on the VCB proxy server, which can be time consuming and requires adequate disk space to hold the full image backup file.

Backups from the ESX Server Service Console

For installations that do not use a SAN, and other environments where Consolidated Backup will not be used, it is still possible to perform full image backups from the Service Console, with appropriate scripts to utilize the VMware command line interface.

When performing a Full Image backup using vcbMounter from the ESX Service Console, the following occurs:

• The PreScan batch file triggers vcbMounter to:
  • create a snapshot of the Virtual Machine
  • copy a disk image of the Virtual Machine to the destination directory specified in the vcbMounter command line
  • delete the snapshot of the Virtual Machine
• The Linux File System iDataAgent on the ESX Server backs up the full disk image file(s)
• An optional PostBackup batch file can be used to delete the disk image(s)

When performing a Full Image backup using vcbSnapshot from the ESX Service Console, the following occurs:

• The PreScan batch file triggers vcbSnapshot to:
  • create a snapshot of the Virtual Machine
  • mount the snapshot directly to the ESX Server
• The Linux File System iDataAgent on the ESX Server backs up the full disk image
• The PostBackup batch file triggers vcbSnapshot to unmount and delete the snapshot of the Virtual Machine

Benefits

• Does not require a SAN. Any Virtual Machine residing on a VMFS datastore can be backed up.
• No VCB Proxy Server(s) required.
• Full Image backups are performed using standard VMware command line utilities with the Linux File System iDataAgent installed on the Service Console.
• Full Image backups can be performed for all guest operating systems.
• Alternate method of Full Image backup using vcbSnapshot directly backs up the snapshot of the Virtual Machine's VMFS disk image on the datastore. Total backup time is greatly reduced as no new image file set is created, and no additional disk space is needed except what is required to maintain the snapshot file.
• File backups are performed using the appropriate iDataAgent(s) installed directly on the Virtual Machine. Refer to the documentation appropriate for the guest operating system and data to be protected.

Considerations

• Backups are performed on the ESX Server computer, increasing its processor load.
• Full Image backup using vcbMounter requires adequate disk space to hold the backup image created by VMware vcbMounter command on the ESX server.
• ESX Server contains a built-in firewall, which is on by default. Although the Security Configuration has exceptions for the installed iDataAgent(s), if you choose to use the firewall, it will still be necessary to configure the firewall options on the VMware Service Console as well as the CommServe and MediaAgent(s) with which the iDataAgent on the Service Console will communicate. Note that backup and restore performance will be degraded by the firewall.
• The alternate method of Full Image backup using vcbSnapshot is not compatible with vcbRestore; it simply backs up the Virtual Machine as a flat file.

Backups from the Virtual Machine

Data can be backed up directly from a Virtual Machine by installing the appropriate iDataAgent(s) directly on the Virtual Machine in the usual manner; follow the standard procedures for installing and using each particular supported iDataAgent. For more information about which iDataAgents are supported for installation in a Virtual Machine, see System Requirements.

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