An LPAR, or logical partition, is an IBM virtual machine. LPARs run on a variety of IMB hardware and provide strong isolation between partitions. This article describes a method for quickly building LPARs running AIX on IBM pSeries hardware
AIX can be installed onto an LAPR using the distribution CDs (or rather, since this is a virtual machine, the ISO image files derived from those physical CDs). There are, however, two drawbacks with this:
- it does not include site specific customizations. If a piece of software like Apache or ssh is required on the LPAR, it must be installed separately – a pain if you have many LPARs to build.
- it is a slow process. AIX is supplied spread over several CDs. The administrator must swap CDs several times during the installation. This means hanging around and typing commands needed to mount and dismount the cd ISO images on the target LPAR, something that will have to be done several times during the installation.
Rob McNelly describes a procedure that addresses the first point in his post about The Handy mkcd Command. To summarize: The mkcd command is run on a “source” system that already includes all the desired software and configurations. Several CD ISO files are produced, containing between them all the information on the source system. An LPAR subsequently installed from these bootable ISO files will be a duplicate of the source system, containing all of the desired software and configurations.
With a small adjustment, the procedure can address the second point as well. A -L” argument is added to mkcd, causing the command to produce DVD ISO files, rather than the smaller CD files. An example follows.
First make an area to store the large files produced by mkcd, say “/backup”, then:
# mkcd -e -M /backup -C /backup -I /backup -V rootvg -R -L -S
Initializing mkcd log: /var/adm/ras/mkcd.log...
Verifying command parameters...
Creating image.data file...
Creating mksysb image...
Creating list of files to back up..
Backing up 37744 files..............................
27419 of 37744 files (72%).......
37744 of 37744 files (100%)
0512-038 mksysb: Backup Completed Successfully.
Populating the CD or DVD file system...
Copying backup to the CD or DVD file system...
.......
Building chrp boot image...
Creating Rock Ridge format image: /backup/cd_image_323726
Running mkisofs ...
........
mkrr_fs was successful.
Making the CD or DVD image bootable...
The above procedure will produce a single ISO several Gb in size. This can be used as an installation DVD for future LPARs. The installation can be unattended because it will not be necessary to change the CD/DVD, and the resultant system will contain all of the desired software and configurations that were present on the source system.
To use the DVD image on P series hardware, transfer the ISO file to the vio, build an LPAR, mount the DVD onto it, reboot and follow the installation instructions. Like a normal installation.