A potential for dataloss has been found in PureDisk Remote Office Edition 6.5.1 when Time-Based Data Removal Policies are used. Only latest version of each file will be kept, regardless of the Time Based removal setting. For files deleted from the agent, no versions are kept after data removal.

Article:TECH69005  |  Created: 2009-01-23  |  Updated: 2010-01-31  |  Article URL http://www.symantec.com/docs/TECH69005
Article Type
Technical Solution


Environment

Issue



A potential for dataloss has been found in PureDisk Remote Office Edition 6.5.1 when Time-Based Data Removal Policies are used. Only latest version of each file will be kept, regardless of the Time Based removal setting. For files deleted from the agent, no versions are kept after data removal.

Solution



Introduction:
At this time, it is not recommended to use Time Based Data Removal Workflows with PureDisk 6.5.1, as an issue has been identified with the Data Removal Policies.  

The parameter "Remove versions backed up : Older than (in days)" specified is always interpreted as zero, regardless of the setting.  This means that only the last version of every file is retained after data removal.  For files that are deleted on the source client before the latest backup, no version will be retained at all.  

This issue will lead to incorrect restores when choosing to "Restore version from date" (point-in-time restore). Up to several files could be missing even though the restore completes successfully.  

In the case of choosing "Restore latest version", the restore should be unaffected by this issue as it will restore the files present on the source client at the time of the latest backup.


What is affected:
Only the following version of PureDisk is affected, on all supported platforms:
- NetBackup PureDisk Remote Office Edition 6.5.1

Note: The issue only occurs in PureDisk 6.5.1, not in versions 6.1.x, 6.2.2, 6.5.0 or 6.5.0.1.


How to determine if affected:
Data loss has been known to occur if ALL of the following conditions are met:
- PureDisk 6.5.1 is running on the Storage Pool Authority (SPA)
- Time Based Data Removal policies are using the "Older than (in days)" parameter with a value > 0
- It is later desired to use point-in-time restore to restore older file versions, or files that were deleted on the agent.  These files are not available for restore due to this issue.

Workaround:
Data Removal Policies that use the Time Based 'Older than' parameter with a value greater than 0 should be disabled immediately until the hotfix can be applied. If data removal is necessary, use Version Based Data Removal only.
Note that when data removal policies are disabled or modified, available disk space will be affected and /storage may become full.


Formal Resolution:
Symantec has acknowledged that the above mentioned issue (Etrack 1557553) is present in the current version(s) of the product(s) mentioned at the end of this article. Symantec is committed to product quality and responsiveness to customers. This issue is addressed in the following release:
- NetBackup PureDisk 6.5.1.1 hotfix (currently available)

6.5.1.1 is available in the Related Documents section below and also at the following location:

It is recommended to apply 6.5.1.1 as soon as possible if potentially affected by this issue.  If PureDisk 6.5.1.1 or a workaround cannot be applied, please contact Symantec support, referencing this TechNote ID and Etrack 1557553 to obtain a fix for this issue.
Please note that the formal resolution will prevent this issue from occurring in the future, but cannot recover files that are missing due to this issue.


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.


How to Subscribe to Software Alerts:
If you have not received this TechNote from the Symantec Email Notification Service as a Software Alerts, please subscribe at the following link:    
 http://maillist.entsupport.symantec.com/subscribe.asp

Supplemental Materials

SourceETrack
Value1557553
DescriptionETrack 1557553 (Time Based Data Removal Workflow removes ALL versions of data that is 'deleted on source' irrespective of time backed-up.


Legacy ID



321408


Article URL http://www.symantec.com/docs/TECH69005


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