Understanding and configuring TXSeries SFS volumes.

Usually TXSeries users would configure TXSeries regions to meet their architecture requirements. But users miss to configure and tune SFS volumes (both data and log volumes). Whenever a default region (SFS Server as File Manager) is created in TXSeries, SFS Server with the hostname is also created with default settings. Default settings include SFS Log Volume size and SFS Server Data Volume size.

SFS Log Volume is used to store a SFS Servers log files. The data in this volume is used during recovery of transactions. The recovery data typically would include non-committed SFS Server data.

SFS Data Volume is used to store a SFS Severs application data. Committed data in SFS Server is stored in SFS Server’s data volume.


If the SFS Server fails to commit the data to data volume then the SFS log volume is used during the recovery process. Once the data is committed in data volume, entries in the log volumes are deleted. A typical setting of log volume size could be something like 100MB and data volume size as 2GB.

Steps to follow for configuring SFS Server’s volume size.

Before creating the SFS Server, understand how much log volume and data volume size is necessary for your architecture. In this example, im setting SFS log volume size as 128MB and SFS data volume size as 1GB.

a) Set the environment variable CICS_SFS_LOGICAL_PARTITION_SIZE to Physical partition size in the machine. Physical partition size can be obtained by running ‘lsvg rootvg’ command.
export CICS_SFS_LOGICAL_PARTITION_SIZE=64

b) Set the environment variable CICS_SFS_LOG_SIZE to 128MB . This environment variable takes input in MB
export CICS_SFS_LOG_SIZE=128

c) Set the environment variable CICS_SFS_DATA_SIZE to 1024 MB(1 GB). This environment variable takes input in MB
export CICS_SFS_DATA_SIZE=1024

For any further information on this, refer TXSeries Infocenter documentation.