====== WPAR Introduction ======

==== What is a WPAR ====

A WPAR is a level higher in the virtualization. Available since AIX 6.1, it allows to host on a single OS up to 8000 WPAR. System WPAR can be used for most application that don't use physical resources. 

WPAR has appear with AIX 6.1. There are 2 types of WPAR: 
  * **application WPAR**, which isolate an application and can have it own IP address. It exist only while the application is up. Few used, because you can't login.
  * **system WPAR**, which give you a fully virtualized OS with minimum management and few devices. It has his own IP, and is compliant for with most applications (Oracle,DB2...)

==== WPAR Improvements ====

WPAR improvements with the AIX 6.1 and later operating systems

|AIX 6.1 Base Level (GA)|- Initial support, including mobility using synchronous checkpoint/restart|
| |- First WPAR manager release|
|AIX 6.1 TL1|- Network File System (NFS) support for WPAR|
|AIX 6.1 TL2|- Asynchronous mobility|
| |- Per-WPAR routing|
| |- Name-mapped network interfaces|
| |- Network Installation Management (NIM) support for WPAR|
|AIX 6.1 TL3|- Storage disk devices support|
|AIX 6.1 TL4|- rootvg WPAR|
| |- SAN mobility|
| |- WPAR manager integration with IBM Systems Director|
| |- VxFS support|
|AIX 6.1 TL5|- WPAR Error Logging Framework (RAS)|
|AIX 6.1 TL6|- Virtual SCSI (vSCSI) disk support|
| |- WPAR migration to AIX 7.1|

|AIX 7.1 Base Level (GA)|- Everything that is supported in AIX 6.1, plus Fiber Channel (FC) adapter support, Versioned WPARs running AIX 5.2, and Trusted Kernel extension support AIX version WPAR improvement|
|AIX 7.1 TL1|- Versioned WPARs running AIX 5.3|

Since AIX 6.1 TL4, you can create a system WPAR with his own rootvg (/usr and /opt not shared); this method is used on AIX 7.1 to virtualize WPAR in AIX 5.2 and 5.3.