A potential for data loss has been found when running VMWare consolidated backups (VCB) in NetBackup 6.5GA and above. Drives which are excluded from the proxy client are also excluded from the Virtual Machines that the proxy client hosts.

Problem

A potential for data loss has been found when running VMWare consolidated backups (VCB) in NetBackup 6.5GA and above. Drives which are excluded from the proxy client are also excluded from the Virtual Machines that the proxy client hosts.

Solution

Overview:
A potential for data loss has been found when running VMWare consolidated backups (VCB) in NetBackup 6.5GA and above.  Drives that are excluded from the proxy client are also excluded from the Virtual Machines that the proxy client hosts.


What is affected:
The following versions of NetBackup are affected on all supported Windows Client platforms:
- NetBackup Server / Enterprise Server 6.5GA and above.

Note: Due to the fact that a fix is being investigated, it is not yet confirmed which NetBackup Release Update will contain a fix or if the next Major Release of NetBackup will be affected by this issue.  Efforts are currently underway to provide an emergency fix.  As with all releases, please view the readme as releases are made in order to confirm any known issues.  


How to determine if affected:
Data loss has been known to occur if ALL of the following conditions are met:
- NetBackup Server / Enterprise Server 6.5GA and above is being run on the client.
- A Backup policy is set to FlashBackup-Windows, using either a Type 0 (full or incremental) or a Type 3 (incremental) virtual machine backup type.
- One or more drive letters are configured to be excluded on the proxy client.
- These same drive letters exist on one or more Virtual Machines that are backed up with this policy via the proxy client.

If the above conditions are met, excluded drive letters will be skipped on the proxy client as expected, but also for any Virtual Machines that the proxy client hosts.


Example:
Suppose that drives C: and D: are set to be excluded from an affected Windows proxy client that hosts 4 Windows virtual machines.  If the conditions above are met, C: and D: will be excluded from the Windows proxy client as expected.  However, the C: and D: drives within all of the 4 VM's hosted from this proxy client will also be excluded.


Workaround:
At this time, the suggest workaround is to not perform drive exclusions of affected Windows clients until a fix can be applied.  


Formal Resolution:
The formal resolution to this issue (Etrack 1876316) will be included in the following releases:
-  NetBackup 7.0, currently available.
-  NetBackup 6.5 Release Update 6 (6.5.6), scheduled for release during the second quarter of 2010.

As new product updates are released, please visit the following link for download and readme information:
 http://www.symantec.com/business/support/overview.jsp?pid=15143

To ensure this issue is not exhibited on any affected versions, or potentially affected future releases, it is strongly recommended to utilize the workaround above.  Also, please note that when a fix is available and applied, it will prevent this issue from initially occurring but cannot recover data that was skipped due to this issue.


Best Practices:
Symantec strongly recommends the following best practices:
1. Always perform a full backup prior to and after any changes to your environment
2. Always make sure that your environment is running the latest version and patch level
3. Perform periodic "test" restores
4. Subscribe to technical articles / alerts


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