IBM Tivoli Storage FlashCopy Manager for UNIX and Linux, Version 4.1

Capacity planning

Ensure that there is sufficient storage space before you install and use IBM® Tivoli® Storage FlashCopy® Manager.

The storage space that is required for Tivoli Storage FlashCopy Manager can be divided into the following categories:

Space that is required for the global product installation on the system.
Space that is required to enable each individual database instance or custom application instance with Tivoli Storage FlashCopy Manager. This enablement is referred to as activation.
Space that is required on the storage system or in the GPFS file system to store the actual snapshot backups or clones.

Space requirement for global product installation

The space that is required for the product installation of Tivoli Storage FlashCopy Manager varies depending on the underlying operating system. The following table shows the default installation paths and the average space requirements.

Table 1. Space requirements for a global product installation of Tivoli Storage FlashCopy Manager
Operating system	Default installation path	Space required (MB)
AIX®	/usr/tivoli/tsfcm/acs_`version_number`	1100
Solaris	/opt/tivoli/tsfcm/acs_`version_number`	700
Linux	/opt/tivoli/tsfcm/acs_`version_number`	500
HP-UX	/opt/tivoli/tsfcm/acs_`version_number`	1900

Space requirement for database instance or custom application installation

Tivoli Storage FlashCopy Manager must also be installed on each database and custom application instance that is enabled for snapshot-based data protection or cloning. This process is called activation and occurs during the installation. During this process, all necessary files are copied from the installation path to a database instance-specific or custom application-specific installation directory. The space that is required for each Tivoli Storage FlashCopy Manager enabled application is approximately equal to the amount of space that is required for the global product installation.

Tivoli Storage FlashCopy Manager must also be installed on application instances that are running on a backup server, unless it shares its Tivoli Storage FlashCopy Manager installation with the production server by using a Network file system (NFS).

Extra space is required for Tivoli Storage FlashCopy Manager log files. Log files are written continuously by Tivoli Storage FlashCopy Manager without automatically deleting the older ones. You must monitor periodically the amount of space that is used by these log files and manually delete them if required.

Space requirement for snapshot copies

The snapshot copies of your application data or databases require the most space. The space that is required depends on the following factors:

The total size of all storage system source volumes that are part of the volume group on the storage system. The volume groups contain the application data.
The type of snapshot whether it is a full copy or a space-efficient snapshot.
The number of backup copies.
The number of changes that occur on the source volumes after a snapshot is taken. This factor applies to space-efficient snapshots only.
In an IBM DB2® pureScale® environment, snapshots are stored in the GPFS file system. Therefore, the GPFS file system must have sufficient free space to store all snapshots. The size of a snapshot depends on the number of changes to the GPFS file system content that occur after the snapshot was taken. As a consequence, space requirements for a single snapshot can increase over time.

Use the MAX_VERSIONS parameter in the Tivoli Storage FlashCopy Manager profile configuration file to limit the number of snapshots that are stored on a storage system or in a GPFS file system.

On SAN Volume Controller, IBM Storwize® V7000, and IBM System Storage® DS8000®, full snapshot copies require the same amount of space as the corresponding source volumes.

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