Steps to increase zFS File System size dynamically in the WebSphere Application Server (WAS) on zOS

The 'zFS' stands for zSeries File System. It's newest Portable Operating System Interface (POSIX)-style hierarchical file system for IBM's z/OS operating system. The zFS as a separate entity was initially released as PTFs (patches) for z/OS 1.2.
But now the zFS is included as a standard feature beginning with z/OS 1.3.

Step 01) Go to bin directory of WebSphere Application Server(WAS) base installation
Look for 'zCreateConfigFileSystem.sh' script at given locations-

/WAS800/zWebSphere/V8R0/bin  (For WAS8)
/WAS850/zWebSphere/V8R5/bin  (For WAS8.5)

Step 02) Edit 'zCreateConfigFileSystem.sh' script
Add EXTADDR parameter in the script as shown below in the red colour-

# ZFS configuation file system requested
else
        # Define vsam linear data set
        printMessage CWLCS0023I "$fileSystemName"
        if [[ -z "$volume" ]]; then
                zfsadm define -aggregate "$fileSystemName" -cylinders "$primaryCylinders" "$secondaryCylinders" -dataclass EXTADDR
        else
                zfsadm define -aggregate "$fileSystemName" -volumes "$volume" -cylinders "$primaryCylinders" "$secondaryCylinders" -dataclass EXTADDR
        fi

Step 03) Save the script file.
Now whenever ZFS File System will fall short of size, it will dynamically grow in size to to accommodate as per the new requirements.