A potential for data loss has been found in PureDisk 6.6 and 6.6.0.1. "Deleted entries" in the PureDisk Metabase may cause files to be deleted prematurely. PureDisk Deduplication Option (PDDO) is not affected.

Article:TECH77713  |  Created: 2010-01-10  |  Updated: 2010-01-10  |  Article URL http://www.symantec.com/docs/TECH77713
Article Type
Technical Solution

Product(s)

Environment

Issue



A potential for data loss has been found in PureDisk 6.6 and 6.6.0.1. "Deleted entries" in the PureDisk Metabase may cause files to be deleted prematurely. PureDisk Deduplication Option (PDDO) is not affected.

Solution



Introduction:
After a Windows client backup, "deleted entries" are added to the PureDisk Metabase, although the files or folders for these entries are still on the client's file system.  If any incorrect "deleted" entries in the database are processed by data removal, data may be removed prematurely and become unavailable for restore even though backups have completed successfully.  PDDO is not affected by this issue. When this issue is seen, drive letters will be missing when browsing to restore data for the client in question.

What is affected:
- PureDisk 6.6 and 6.6.0.1 on all supported Windows client platforms


How to determine if affected:
Data loss has been known to occur if ALL of the following conditions are met:
- The PureDisk versions mentioned above are being run on a Windows agent.
- Files and/or folders selected for backup on multiple drive letters, or a full system backup is configured for an agent with multiple drive letters
- Snapshots are enabled for the agent
- Drive letters appear to be missing when browsing to restore files for the agent
- Data removal meets its retention for the agent's data

If the above conditions are met, data removal and Metabase (MB) garbage collection policies should be disabled and Technical Services should be contacted. When this issue is encountered, multiple-drive dataselections will be missing file and folder data.  Additionally, very large polist.po files (as large as 5 to 80GBytes) will be seen on the client-side under the "tmp" and "var" sub-folder of the installation path.  Due to the fact that these files grow to a large size, backups may fail due to lack of drive space.  If no missing drive letters are seen, there is no sign of immediate data loss.  However, if the first three conditions above have been met, it is strongly recommended to contact Technical Services to ensure the configuration is not potentially affected.

Note:  If the affected data selections are replicated to a different storage pool, the replicated data selections will also be affected.


Workaround:
If the above conditions are met, please disable all data removal and Metabase (MB) garbage collection policies and contact Technical Services.  If the Formal Resolution (below) is not yet available or feasible to apply, reference this TechNote ID (338287) and Etrack 1901224 for an Emergency Fix and further instructions.


Formal Resolution:
Symantec has acknowledged that the above mentioned issue (Etrack 1912529) is present in the current version(s) of the product(s) mentioned at the end of this article.  This is address in version 6.6.0.2, available in the related documents section, below.

NOTE:  If 6.6.0.2 is applied to address this issue, it is still recommended to disable all data removal and Metabase (MB) garbage collection policies and contact Technical Support as soon as possible.


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


Article Subscription:
Subscribe to this TechNote for any updates that are made to this article, by clicking on the following link:
 http://maillist.support.veritas.com/notification.asp?doc=338287


Software Alerts:
If you have not received this from the Symantec Technical Support Email Notification Service, please click on the following link to subscribe to future Notifications:
 http://maillist.entsupport.symantec.com/subscribe.asp


Supplemental Materials

SourceETrack
Value1912529
DescriptionAll backed up drives not showing up on PureDisk GUI. Q:\ and C:\ backed up but only Q:\visible


Legacy ID



338287


Article URL http://www.symantec.com/docs/TECH77713


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