Using an alternate HFS structure to upgrade WebSphere Application Server for z/OS

Before you begin

This task is the second of the two methods for performing a rolling upgrade of WebSphere Application Server for z/OS in a sysplex that is introduced by Installing new releases and maintenance levels of WebSphere Application Server for z/OS. Using a version-specific HFS structure to upgrade WebSphere Application Server for z/OS describes the first method. This task describes using an alternate HFS structure to upgrade WebSphere Application Server for z/OS.

Why and when to perform this task

The alternate HFS structure accomplishes the same objective as the version-specific HFS structure, but does not mount a product HFS directly off the version-specific subdirectories (referred to by the $VERSION symbolic link). Rather, version-specific subdirectories refer to system-specific subdirectories using symbolic links with the $SYSNAME symbol. In turn, system-specific subdirectories refer to program product subdirectories through symbolic links. The alternate HFS structure is depicted in the following illustration:

Alternate HFS structure

The alternate HFS structure has the following characteristics:

With the alternate HFS structure in place, you can mount one or more code levels of WebSphere Application Server for z/OS, Java, or DB2 for OS/390 (JDBC) under their individual component subdirectories. Each system-specific subdirectory uses symbolic links to component code levels and can refer to new code levels by changing those symbolic links.

There are certain advantages to the alternate HFS structure:

Example: Assume you have an individual component directory for WebSphere Application Server for z/OS (/WebSphere), Java (/Java), and DB2 for OS/390 (JDBC) (/DB2). Assume that each directory contains two subdirectories, one for PTFx (/PTFx) and one for PTFy (PTFy). Also assume that the code for each component update is in its own HFS data set, such as OMVS.PTFX.WEB.HFS, OMVS.PTFX.JAVA.HFS, and OMVS.PTFX.JDBC.HFS, for example. The mount commands are:

MOUNT FILESYSTEM('OMVS.PTFX.WEB.HFS')   MOUNTPOINT('/WebSphere/PTFx') TYPE(HFS) MODE(RDWR)
MOUNT FILESYSTEM('OMVS.PTFX.JAVA.HFS')  MOUNTPOINT('/Java/PTFx')      TYPE(HFS) MODE(RDWR)
MOUNT FILESYSTEM('OMVS.PTFX.JDBC.HFS')  MOUNTPOINT('/DB2/PTFx')       TYPE(HFS) MODE(RDWR)

MOUNT FILESYSTEM('OMVS.PTFY.WEB.HFS')   MOUNTPOINT('/WebSphere/PTFy') TYPE(HFS) MODE(RDWR)
MOUNT FILESYSTEM('OMVS.PTFY.JAVA.HFS')  MOUNTPOINT('/Java/PTFy')      TYPE(HFS) MODE(RDWR)
MOUNT FILESYSTEM('OMVS.PTFY.JDBC.HFS')  MOUNTPOINT('/DB2/PTFy')       TYPE(HFS) MODE(RDWR)

System SYS1 refers to the PTFx levels of code through these symbolic links:

/WebSphere --> /WebSphere/PTFx
/Java      --> /Java/PTFx
/DB2       --> /DB2/PTFx

If you want system SYS1 in the sysplex to use the HFS structure associated with PTFy, change the symbolic links for /WebSphere, /Java, and /DB2:

/WebSphere --> /WebSphere/PTFy
/Java      --> /Java/PTFy
/DB2       --> /DB2/PTFy

Use the following procedure to switch the code level for the WebSphere Application Server for z/OS for the clustered host instance on SYS1.

Steps for this task

  1. Install the new code for WebSphere Application Server for z/OS, Java, and DB2 for OS/390 (JDBC), copy each component to its own data set, and mount the data under its component subdirectory.
    WebSphere Application Server for z/OS, Java, and DB2 for OS/390 (JDBC) code levels are usually interdependent, so keep the level of each component coordinated with the others.
  2. Shut down all Application Servers and the WebSphere Application Server for z/OS clustered host instance on SYS1.
  3. Change the symbolic links for the system-specific subdirectories for SYS1.
  4. Load new run-time modules into LPA and update the link list. You can do this dynamically, but IBM recommends you re-IPL the system.
  5. Change the start procedures to address the new code level load libraries.
  6. Restart WebSphere Application Server for z/OS and the Application Servers.

Results

By repeating this process for each clustered host instance, one at a time, you can upgrade the code level of WebSphere Application Server for z/OS throughout the sysplex without disrupting service to your clients.

What to do next


Related tasks
Using a version-specific HFS structure to upgrade WebSphere Application Server for z/OS



Searchable topic ID:   tins_altdualhfsov
Last updated: Jun 21, 2007 9:56:50 PM CDT    WebSphere Application Server for z/OS, Version 5.0.2
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