VMware Agent backup of a virtual machine may fail with error 0xe000959b when VMware is unable to create a snapshot due to the freeze or thaw script used for preparing the guest operating system for the snapshot is not called correctly from VMware.

Article:TECH136415  |  Created: 2010-01-08  |  Updated: 2013-02-12  |  Article URL http://www.symantec.com/docs/TECH136415
Article Type
Technical Solution


Issue



VMware Agent backup of a virtual machine may fail with error 0xe000959b when VMware is unable to create a snapshot due to the freeze or thaw script used for preparing the guest operating system for the snapshot is not called correctly from VMware.


Error



0xe000959b - An attempt to take a snapshot of a virtual machine failed because it was unable to quiesce a file system


Cause



Upon installing the Backup Exec Remote Agent for Windows Servers on a Virtual Machine's guest operating system, BAT files are placed in a directory (According to the version of VMWARE as shown in Table 1) that is available for VMWARE to use to run scripts before and after the SNAPSHOT process that aids in getting the guest operating system to pause the activity in Windows so that the snapshot can occur without interruption.


Table 1
 
VMWARE version Script location
ESX 3.5 update 1 and earlier C:\Windows
ESX 3.5 update 2 and later C:\Program Files\VMware\VMware Tools\backupScripts.d

The names of these files are as shown in Table 2

Table 2
 
VMWARE version Script name
ESX 3.5 and earlier PRE-FREEZE-SCRIPT.BAT / POST-THAW-SCRIPT.BAT
ESX 4.0 and later FREEZE.BAT

When Backup Exec sends a backup request to VMWARE, then VMWARE goes to search for the existence of these files.  If they exist, the BAT files will be run by VMWARE before and after the snapshot creation.  If there is an issue running the scripts, the snapshot creation will not succeed and cause the backup to fail.  The following error can be seen in the TASK & EVENTS tab for the CREATE VIRTUAL MACHINE SNAPSHOT event on the virtual machine that was selected for backup.
 
CREATING A QUIESCED SNAPSHOT FAILED BECAUSE THE (USER-SUPPLIED) CUSTOM PRE-FREEZE SCRIPT IN THE VIRTUAL MACHINE EXITED WITH A NON-ZERO RETURN CODE

Solution



  • These files can be attempted to be run manually to confirm that they do not have any issues.  If they do run then the problem is with VMWARE attempting to call the scripts.
  • If the scripts fail, Reinstall the VMWare integration tools.
  • Another way to confirm that the issue is with the calling of these scripts is by moving the two BAT files to a different directory and then attempting to run the backup job again.  If the backup runs successfully, the issue is with VMWARE attempting to call the scripts.
  • If the above files are missing, Reinstall the Remote Agent for Windows Servers(RAWS)
  • RAWS should always be installed after the VMWare tools. 
  • If marges your existing scripts, It inserts before script of symantec.
  • When backs up in the environment where RAWS was installed, PRE-FREEZE-SCRIPT.BAT and POST-THAW-SCRIPT.BAT of "C:\windows" path is used. 

The following VMWARE document link provides information about configuring the PRE and POST scripts on the guest operating system
 http://www.vmware.com/pdf/vi3_35/esx_3/r35u2/vi3_35_25_u2_vm_backup.pdf

We do not recommend modifying the PRE and POST scripts due to the entries entered for preparing the guest operating system for snapshot processing during a backup.  If assistance is needed to customize the scripts, VMWARE Technical Support should be contacted for guidance.

Supplemental Materials

SourceUMI
ValueV-79-57344-38299
Description

An attempt to take a snapshot of a virtual machine failed because it was unable to quiesce a file system.


SourceError Code
Value0xe000959b
Description

An attempt to take a snapshot of a virtual machine failed because it was unable to quiesce a file system.



Legacy ID



355353


Article URL http://www.symantec.com/docs/TECH136415


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