Creating pretask, post-task, and policy scripts

02/24/2021 Contributors

SnapManager enables you to create the scripts for the preprocessing activity, the post-processing activity, and policy tasks of the backup, restore, and clone operations. You must place the scripts in the correct installation directory to execute the preprocessing activity, post-processing activity, and policy tasks of the SnapManager operation.

Pretask and post-task script content

All scripts must include the following:

Specific operations (check, describe, and execute)
(Optional) Predefined environment variables
Specific error handling code (return code (rc))

You must include correct error handling code to validate the script.

You can use the pretask scripts for many purposes, for example, cleaning up a disk space before the SnapManager operation starts. You can also use the post-task scripts, for instance, to estimate whether SnapManager has enough disk space to complete the operation.

Policy task script content

You can execute the policy script without using specific operations such as check, describe, and execute. The script includes the predefined environmental variables (optional) and specific error handling code.

The policy script is executed before the backup, restore, and clone operations.

Supported format

A command file with a .cmd extension can be used as the prescript and post-script.

If you select the shell script file, the SnapManager operation does not respond. To resolve this, you must provide the command file in the plug-in directory, and perform the SnapManager operation again.

Script installation directory

The directory in which you install the script affects how it is used. You can place the scripts in the directory and execute the script before or after the backup, restore, or clone operation takes place. You must place the script in the directory specified in the table and use it on an optional basis when you specify the backup, restore, or clone operation.

You must ensure that the plugins directory has the executable permission before using the scripts for the SnapManager operation.

Activity

Backup

Restore

Clone

Preprocessing

<default_installation_directory>\plugins\backup\create\pre

<default_installation_directory>\plugins\restore\create\pre

<default_installation_directory>\plugins\clone\create\pre

Post-processing

<default_installation_directory>\plugins\backup\create\post

<default_installation_directory>\plugins\restore\create\post

<default_installation_directory>\plugins\clone\create\post

Policy-based

<default_installation_directory>\plugins\backup\create\policy

<default_installation_directory>\plugins\restore\create\policy

<default_installation_directory>\plugins\clone\create\policy

Sample scripts locations

The following are some samples of the pretask and post-task scripts for the backup and clone operations available in the installation directory path:

<default_installation_directory>\plugins\examples\backup\create\pre
<default_installation_directory>\plugins\examples\backup\create\post
<default_installation_directory>\plugins\examples\clone\create\pre
<default_installation_directory>\plugins\examples\clone\create\post

What you can change in the script

If you are creating a new script, you can change only the describe and execute operations. Each script must contain the following variables: context, timeout, and parameter.

The variables you have described in the describe function of the script must be declared at the start of the script. You can add new parameter values in parameter=() and then use the parameters in the execute function.

Sample script

The following is a sample script with a user-specified return code for estimating the space in the SnapManager host:

@echo off
REM $Id: //depot/prod/capstan/Rcapstan_ganges/src/plugins/windows/examples/clone/create/policy/validate_sid.cmd#1 $
REM $Revision: #1 $ $Date: 2011/12/06 $
REM
REM

set /a EXIT=0

set name="Validate SID"
set description="Validate SID used on the target system"
set parameter=()

rem reserved system IDs
set INVALID_SIDS=("ADD" "ALL" "AND" "ANY" "ASC" "COM" "DBA" "END" "EPS" "FOR" "GID" "IBM" "INT" "KEY" "LOG" "MON" "NIX" "NOT" "OFF" "OMS" "RAW" "ROW" "SAP" "SET" "SGA" "SHG" "SID" "SQL" "SYS" "TMP" "UID" "USR" "VAR")

if /i "%1" == "-check" goto :check
if /i "%1" == "-execute" goto :execute
if /i "%1" == "-describe" goto :describe

:usage:
	echo usage: %0 "{ -check | -describe | -execute }"
	set /a EXIT=99
	goto :exit

:check
	set /a EXIT=0
	goto :exit

:describe
	echo SM_PI_NAME:%name%
	echo SM_PI_DESCRIPTION:%description%
	set /a EXIT=0
	goto :exit

:execute
	set /a EXIT=0

	rem SM_TARGET_SID must be set
	if "%SM_TARGET_SID%" == "" (
		set /a EXIT=4
		echo SM_TARGET_SID not set
		goto :exit
	)

	rem exactly three alphanumeric characters, with starting with a letter
	echo %SM_TARGET_SID% | findstr "\<[a-zA-Z][a-zA-Z0-9][a-zA-Z0-9]\>" >nul
	if %ERRORLEVEL% == 1 (
		set /a EXIT=4
		echo SID is defined as a 3 digit value starting with a letter. [%SM_TARGET_SID%] is not valid.
		goto :exit
	)

	rem not a SAP reserved SID
	echo %INVALID_SIDS% | findstr /i \"%SM_TARGET_SID%\" >nul
	if %ERRORLEVEL% == 0 (
		set /a EXIT=4
		echo SID [%SM_TARGET_SID%] is reserved by SAP
		goto :exit
	)

	goto :exit



:exit
	echo Command complete.
	exit /b %EXIT%

Creating pretask, post-task, and policy scripts

Creating your file...

Sample script