STATUS CODE 156: VMware Consolidated Backup fails with status 156 (snapshot error encountered) reported

Article:TECH56887  |  Created: 2008-01-18  |  Updated: 2010-01-26  |  Article URL http://www.symantec.com/docs/TECH56887
Article Type
Technical Solution


Environment

Issue



STATUS CODE 156: VMware Consolidated Backup fails with status 156 (snapshot error encountered) reported

Error



<8> bpfis: WRN - Cannot create snapshot after waiting for SNAP_LOCK_TIMEOUT: 15 minutes
<4> bpfis: INF - EXIT STATUS 156: snapshot error encountered

Solution



Overview:
A VMware Consolidated Backup (VCB) fails with status 156 reported.


Troubleshooting:
This issue will arise in a busy VCB environment, as only 1 snapshot can occur per a media server when writing to tape.
In future release updates of 6.5.x, throttle features for FullVM and Mapped FullVM backups will be provided - however, it is not suggested to increase the throttle above single digit numbers as the impact on the ESX servers can result in orphan Snapshots.


Log Files:
From the bpfis log:
09:01:06.484 [676.884] fis_lock: lock C:\Program Files\Veritas\NetBackup\vmware_lock F_WRLCK failed: Unknown error (-2)
09:02:06.486 [676.884] get_id_lock: time left to wait is 0 minute
09:02:06.486 [676.884] get_id_lock: get lock timed out...
09:02:06.486 [676.884] bpfis: WRN - Cannot create snapshot after waiting for SNAP_LOCK_TIMEOUT: 15 minutes
09:02:06.486 [676.884] get_id_lock: fis_id = vmmachine1.veritas.com_1199713522
09:02:06.486 [676.884] bpfis: INF - EXIT STATUS 156: snapshot error encountered


Workarounds:
Option #1:
In an environment where multiple VMware jobs are running at the same time, only one Snapshot will occur per media server. Until the first job has released it's Snapshot, the next job will be unable to proceed. To help keep this issue from happening, set the Limit Jobs per Policy attribute in the Policy configuration.

Limit jobs per policy - This policy attribute can be used to limit the number of simultaneous snapshots that occur on each datastore. Different storage environments can support a varying number of simultaneous backups. The recommended number of simultaneous jobs that are configured for each policy/datastore combination will depend on the quality of the storage infrastructure involved. Best practices would dictate that this number should be kept in the low single digits. One technique for determining the maximum number of simultaneous supportable snapshots is to run test backups, gradually increasing the limit jobs per policy attribute until policy creation and deletion no longer reliably occur - or until the I/O impact on the Vms associated with the datastore begins to have a negative impact on the performance of the associated Vms.

Option #2:
It is possible to increase the time that the NetBackup Proxy server will wait before bpfis will timeout. Create the following registry key to increase the timeout:

HKEY_LOCAL_MACHINE\SOFTWARE\VERITAS\NetBackup\CurrentVersion\Config\BACKUP

Create a REG_DWORD Key: SNAP_LOCK_TIMEOUT

Set to the number of seconds (decimal value).


Formal Resolution:
Symantec has acknowledged that the above-mentioned issue 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 satisfied customers. The formal resolution to this issue is included in the following patch releases:
- NetBackup Enterprise Server 6.5.2

This version is available on the Support Web site at:
 http://www.symantec.com/enterprise/support/downloads.jsp?pid=15143

Supplemental Materials

SourceError Code
Value156
Descriptionsnapshot error encountered


Legacy ID



296234


Article URL http://www.symantec.com/docs/TECH56887


Terms of use for this information are found in Legal Notices