Unable to redirect the restore of LUNs on a NetApp Filer

Article:TECH66079  |  Created: 2008-01-16  |  Updated: 2012-04-23  |  Article URL http://www.symantec.com/docs/TECH66079
Article Type
Technical Solution


Issue



Unable to redirect the restore of LUNs on a NetApp Filer.


Error



NDMP Log Message: RESTORE: LUN files can only be restore to qtree root directories.
NDMP Log Message: RESTORE: can't mark as LUN: : Undefined error: 0


Environment



If a LUN has been created in a Qtree folder in a volume and not in the volume root on a NetApp Filer, then any attempt to redirect the restore to another volume will restore the data, but not recreate the LUN correctly on the filer. The Job Log for the restore will show that it completed successfully, however if you expand the NDMP Log section in the Job log it will show.
 NDMP Log Message: RESTORE: LUN files can only be restore to qtree root directories
NDMP Log Message: RESTORE: can't mark as LUN: <lun name>: Undefined error: 0

 


Cause



This issue is caused because when Backup Exec restores the data,  it also restores the path containing the data. This results in the LUN file being restored to a path that is not a Qtree resulting in an inability to recreate the LUN. 
 

Solution



 In the scenario where a LUN was originally created in a volume root, then a redirected restore is possible to a top-level folder (as long as that folder is already a Qtree).

 
In the scenario where the original LUN location is a Qtree folder instead of the volume root, Symantec have now released a Hotfix for Backup Exec 12.5 that allows registry level control of whether or not full path information is restored when restoring NDMP data to a NetApp Filer. As such in order to redirect this type of LUN to a Qtree folder perform the following steps:
 
1) Make sure the intended target folder is a Qtree.
2) Install Service Pack 2 for Backup Exec 12.5, via LiveUpdate or using the link at the bottom of this document.
3) Use regedit to locate HKEY_LOCAL_MACHINE\Software\Symantec\Backup Exec for Windows\Backup Exec\NDMP
4) In the NDMP key, modify (or create if missing) the REG_DWORD value called PreserveTree and set the data of the value to 0
 
Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and server be made prior to making any registry changes.
 
Note: If this value does not exist and an NDMP backup or restore job is run after the Hotfix has been installed, then this value will be automatically created with a default setting of 1.
 
5) Run the redirected restore of your LUN to the Qtree folder
6) Set the PreserveTree value in the registry back to 1 - this is a recommendation against restoring other types of NDMP data where restoring the tree may be important
 

Notes:
The intention is that in a future version of Backup Exec,  the ability to control whether or not a full path will be restored during NDMP jobs will be available in the Backup Exec Console. With both scenarios, the LUN is recreated in an offline state so that it can be mapped to an unused LUN ID, please refer to NetApp's own documentation for more information on mapping LUNs.

 

Supplemental Materials

SourceETrack
Value1478189
Description

NDMP: Unable to redirect the restore of a LUN on a NetApp Filer.



Legacy ID



316576


Article URL http://www.symantec.com/docs/TECH66079


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