Backing up machines with an Agent engages Microsoft VSS to put supported applications into a consistent state during backup. This option ensures that all application write requests in the machine's memory are committed to disk before the snapshot is taken. This ensures the application data can be reliably recovered from the backup.
However, there are applications that are not VSS aware. In cases where you are backing up servers that host non VSS-aware applications, custom quiescing scripts can be used to achieve application-consistent backups.
Windows Registry Disclaimer:
Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 “Description of the Microsoft Windows registry” at Microsoft Support.
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With agent-based protection, a method is provided to execute a script before and after transferring a snapshot.
To run a custom quiescing script on the protected server:
The PreTransferScript.ps1 and PostTransferScript.ps1 can be used to call other scripts or execute statements.
As an example, in KB142501, these scripts are used to quiesce an older Oracle DB.
With agentless protection, Rapid Recovery relies on VMware tools, VMware's snapshot process and VDDK API's.
VMware has provided a way to execute scripts prior to taking and after deleting a VMware snapshot. This allows for the execution of custom quiscing scripts for non vss-aware applications.
To prepare a VM to use custom quiescing scripts:
Default diretories for scripts on Windows virtual machines.
Version of ESXi Custom quiescing script directory ESXi 5.0 C:\Windows\ C:\Program Files\VMware\VMware Tools\backupScripts.d\ ESXi 5.1 and ESXi 5.5 C:\Windows\
Scripts for non-Windows virtual machines.
- Pre-freeze: /usr/sbin/pre-freeze-script
- Post-thaw: /usr/sbin/post-thaw-script
If you are using multiple scripts in the backupScripts.d folder, they will be executed in alphabetical order during the freeze phase and in descending alphabetical order during the thaw phase.
If you are using the backupScripts.d folder, you can have a single bat file that can detect whether to run the freeze or thaw phase. For example, you can have the following in a bat file. The italicized text can be replaced to fit your needs.
if "%1" == "freeze" goto doFreeze
As an example, lets assume that a Domino server needs to be backed up.
Here is a sample pre-freeze script that will drop connected users and will also flush the cache for a Domino server.
"C:\Program Files\IBM\Lotus\Domino\nserver.exe" -c "drop all"
timeout /t 5 /nobreak
"C:\Program Files\IBM\Lotus\Domino\nserver.exe" -c "dbcache flush"
timeout /t 5 /nobreak