Details:
Overview:
A potential for data loss has been discovered in NetBackup Server/Enterprise Server 6.5.4 where DFSR paths may be skipped on backup, yet report a Status 0.  This has been observed when the DFSR path exceeds 256 characters.  

This only occurs when backing up DFSR via Shadow Copy.  This method was introduced in 6.5.4 (see technote 326098 below).


What is affected:
The following versions of NetBackup are affected by this issue, on all supported Windows platforms:

- NetBackup Server/Enterprise Server 6.5.4
- NetBackup Server/Enterprise Server 6.5.5
- NetBackup Server/Enterprise Server 7.0 *

* Note:  Due to release timing, it cannot be fully confirmed at this time if the release will be affected by this issue.  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 can occur if ALL of the following conditions are met:

- The NetBackup Client is one of the affected servers mentioned above, running on a supported Windows DFSR platform
- The Shadow Copy method of backing up DFSR is used
- One or more of the DFSR Shadow Copy paths exceed 256 characters
- The DFSR data is later required for restore.

If the above conditions are met, the backup has been known to end in Status 0 even though the path with excessive characters is skipped.  In some cases, the client's bpbkar process may fault and the backup could end in a Status 13 (file read failed).  Therefore, if the above conditions are met, the backup may end in Status 0 or Status 13 if a fault condition occurs from the excessive characters.

Log files:
A review of the bpbkar log shows that when a path of greater than 256 characters is included as part of the backup set, it is unable to locate the first file to be backed up.

Any of the following object paths that exceed 256 characters will be skipped:

Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders\<remainder of path causing path to exceed 256 characters>

When a backup of the path is performed, the backup process (bpbkar) may be unable to find the first file in the path:

1:47:42.821 PM: [1260.3432] <4> dos_backup::tfs_findfirst: WRN - unable to find first file:
'Shadow Copy Components:\User Data\Distributed File System Replication\DfsrReplicatedFolders\1234567890abcdef\
234567890abcdef134567890abcdef12\4567890abcdef123567890abcdef1234\67890abcdef12345\7890abcdef123456\
890abcdef1234567\90abcdef123456780abcdef123456789\1234567890abcdef\234567890abcdef1\34567890abcdef12\
4567890abcdef123\567890abcdef1234'

1:47:42.821 PM: [1260.3432] <2> ov_log::V_GlobalLog: INF - v_beds::V_FindNext() EXIT Name: bRC:false LastError:0xFFFFFE07:0xa000fe07 (2684419591)

Workaround:
There are 2 separate workarounds available:

Workaround A: Verify that any DFSR paths being backed up do not exceed 256 characters.

Workaround B: Use the workaround of disabling the DFSR Service.  This is detailed in TechAlert 290900 (http://support.veritas.com/docs/290900)

If these workarounds are not feasible, please call Technical Services (Referencing this TechNote and Etrack 1874894) to discuss an engineering binary.  If an engineering binary is applied to address this issue, please confirm with Technical Services if additional binaries are required before upgrading NetBackup to a newer version.


Formal Resolution:
Symantec has acknowledged that the above-mentioned issue (Etrack 1874894) is present in the current version(s) of the product(s) mentioned at the end of this article. Symantec Corporation is committed to product quality and satisfied customers. This issue is currently being considered by Symantec Corporation to be in the following Release Update of the product:

-  NetBackup Server/Enterprise Server 6.5.6

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=336578


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

Related Documents:

290900: TECHALERT: Backups of Distributed File System Replication (DFSR) data on Windows 2003 R2 using NetBackup 6.5 GA - 6.5.3.1 complete with a NetBackup Status Code 0 (successful), but the data is not backed up.
 http://support.veritas.com/docs/290900


326098: DOCUMENTATION: Protecting Distributed File System Replication (DFSR) data with NetBackup 6.5.4
 http://support.veritas.com/docs/326098

Supplemental Material:

System: Ref.#	Description
ETrack: 1874894	1874894: DFSR backup faults bpbkar.exe
Error Code: 13	file read failed

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