The backup of Lotus Domino databases with extremely large numbers of associated NLO files fails with error 'Backup Exec cannot determine the NLO files that one or more Lotus Domino databases refer to'

Article:TECH136835  |  Created: 2010-01-21  |  Updated: 2014-09-25  |  Article URL http://www.symantec.com/docs/TECH136835
Article Type
Technical Solution


Issue



The backup of Lotus Domino databases with extremely large numbers of associated NLO files fails with error 'Backup Exec cannot determine the NLO files that one or more Lotus Domino databases refer to'


Error



E0009A91 - 'Backup Exec cannot determine the NLO files that one or more Lotus Domino databases refer to'


Cause



This issue occurs when backing up Lotus Domino databases that are Domino Attachment and Object Service (DAOS) enabled and have extremely large numbers of associated NLO files.  Two issues can occur as a result of this situation.  First, the job will fail with the error referenced in this Technote because all the NLO files for a database have not been enumerated in the allowed time.  This timeout may be increased with a registry setting per Technote 354974, http://www.symantec.com/docs/TECH130647.  If the timeout is increased per the registry setting, the backup jobs may become unacceptably slow because of the large numbers of NLO files that are enumerated for each database backed up.


Solution



This issue has been resolved with Hotfix 351400 for Backup Exec 2010.  See related documents for more information.


Notes:

Once Hotfix 351400 has been applied, the Backup Exec server contains the ability to selectively gather NLO information about Domino databases with a new registry setting.  Below are the allowable settings for this registry value and their effect.

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 workstation be made prior to making any registry changes.

The setting value is located here:

HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Backup Exec For Windows\Backup Exec\Engine\Domino\DAOS listnlo mode

The value may be 0, 1, 2, 3 as follows:

0      Default value.
Using this value does not change the Domino Agent's default behavior. Backup jobs continue to function as normal. The NLO references are determined for each database selected for backup. However, large numbers of NLO references can cause the backup jobs to fail due to the LISTNLO timeout period being exceeded. This value should be used when a small number of NLO references are associated with the Domino databases. Use this value if each database is expected to have less than 30,000 NLO references. Note that this number can be higher for full Domino server backup jobs as the Domino Agent can optimize full Domino server backups. It cannot, however, optimize partial Domino server backups. Restore jobs run normally. The required NLO files are restored even with partial Domino server restore jobs. Any missing NLO reference files that cannot be recovered in a Domino recovery are reported for each Domino database that you restore. Keep in mind that by using the value of 0, large numbers of NLO references that you attempt to restore can also cause the restore job to fail due to the default LISTNLO Timeout period elapsing (again, see www.symantec.com/docs/TECH130647 )

1     No LISTNLO during backups
Using this value forces the Domino Agent not to call LISTNLO during backups. When this value is set, LISTNLO is never called for either full or partial Domino server backup jobs. As a result, NLO references are not determined for the Domino databases. Additionally, both full and partial Domino server backup jobs result in all NLO files in the DAOS folder being backed up since NLO references for databases selected for backup have not been determined. Restores from such backup sets may show changed behavior, especially with partial Domino server restores due to the absence of determining NLO references at backup time. Not all NLO files referenced by databases may be restored with a database restore; however the Domino Agent will generate a warning and report the missing NLO files which can be manually restored. Using this value does not change the Domino Agent's default behavior for restore jobs that involve backup sets that were created using the value of 0 or 2 with this registry key.

2     No LISTNLO during restore
Using this value does not change the Domino Agent's default backup behavior. Backup jobs continue to function as normal. The NLO references are determined for each database selected for backup. However, large numbers of NLO references can cause the backup jobs to fail due to the LISTNLO timeout period being exceeded. This value should be used when a small number of NLO references are associated with the Domino databases. Use this value if each database is expected to have less than 30,000 NLO references. Note that this number can be higher for full Domino server backup jobs as the Domino Agent can optimize full Domino server backups. It cannot however, optimize partial Domino server backups. Full and partial Domino server restore jobs run normally. However, LISTNLO is not called to determine missing NLO references; hence missing NLO references are not reported for any Domino database that you restore. Instead, the Domino Agent reports an exception with the following message: "The Lotus Domino server failed to provide a list of the NLO files that are required by the restored and recovered databases. Determine which NLO files are missing, and then individually restore them."

3     No LISTNLO during backup or restore
Using this value forces the Domino Agent not to call LISTNLO during backup or restore. When this value is set, LISTNLO is not called during full or partial Domino server backup jobs. As a result, NLO references are not determined for the Domino databases. Additionally, both full and partial Domino server backup jobs result in all NLO files in DAOS folder being backed up since NLO references for databases selected for backup have not been determined. However, with incremental backups, only the NLO files that are created after the last full backup job are backed up. Restores from such backup sets may show changed behavior, especially with partial Domino server restores due to the absence of determining NLO references at backup time. Not all NLO files referenced by databases may be restored with a database restore; however the Domino Agent will generate a warning and report the missing NLO files which can be manually restored.. Full and partial Domino server restore jobs run normally. However, LISTNLO is not called to determine missing NLO references. As a result, they are not reported for any Domino database that you restore. Instead, the Domino Agent reports an exception with the following message: "The Lotus Domino server failed to provide a list of the NLO files that are required by the restored and recovered databases.| Determine which NLO files are missing, and then individually restore them.
 


Supplemental Materials

SourceETrack
Value2065151
Description

Lotus: Backup of Database with hundreds of thousands NLOs fails in error suggesting listnlo timeout



Legacy ID



357881


Article URL http://www.symantec.com/docs/TECH136835


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