The IPL type parameter on the NWSD determines the source from which a logical operating system is loaded.
The first thing to understand is that on an iSeries™ server the initial program load (IPL) comes from one of four locations managed by the LPAR configuration. These four locations are called A, B, C, and D. The initial program (which in the case of Linux is the Linux kernel) can be loaded into these locations two ways:
The NWSD itself has a parameter called IPLSRC that specifies from where the logical partition is to be loaded. This parameter can have the following values:
| IPLSRC value | Description |
|---|---|
| A | Load the logical partition from location A. Location A must have been previously loaded with a kernel from Linux. IBM® recommends using the A location to store a stable, known kernel. |
| B | Load the logical partition from location B. Location B must have been previously loaded with a kernel from Linux. IBM recommends using B for testing new kernels |
| D | IBM support reserves this type of IPL for future use. |
| *Panel | The partition is started from the source indicated on the operator's panel. |
| *NWSSTG (network server storage space) | This IPL type is used to start a partition from a virtual disk. i5/OS will find the kernel in the virtual disk and load it in location C. Then the partition will be set to IPL from C. i5/OS searches the first virtual disk connected to the NWSD for a partition marked startable, and of type 0x41 (PReP start.) The contents of this location are loaded in C. If a partition of this type does not exist, the partition will fail. |
| *STMF (stream file) | This IPL type is used to start a partition from a kernel loaded in the i5/OS Integrated File System. Note that the Integrated File System includes files on the Optical (CD) drive on i5/OS. i5/OS will load the specified file into the C location and the partition will be set to IPL from C. This is typically how initial Linux installations are performed. |
The LPAR configuration display can be used to set a logical partition to IPL from four locations. These locations are A, B, C, and D. Currently D is reserved for future use. The IPL type determines which copy of programs your server uses during the initial program load (IPL). These parameter can have the following values:
| IPLSRC values | Description |
|---|---|
| A | Load the logical partition from location A. Location A must have been previously loaded with a kernel from Linux. IBM recommends using the A location to store a stable, known kernel. |
| B | Load the logical partition from location B. Location B must have been previously loaded with a kernel from Linux. IBM recommends using B for testing new kernels. |
| C | This IPL type is typical used when a partition is loading from a network server description (NWSD) or a stream file (STMF). Refer to *NWSSTG for more information on how the C IPL type is used. |
| D | IBM support reserves this type of IPL for future use. |