I was just asked this question by customer and it got me thinking, Items I would include:
- WPAR takes seconds to create and LPARs minutes
- LPARs need setting VIOS LV or LUNs but WPARs add simpler NFS mount points, or can just use Global AIX diskspace options
- LPAR needs 512 to 1GB to boot AIX and a WPAR takes just ~60 MB (yes sixty megabytes)
- You can share application code say 1 GB in each and every LPAR (40 LPAR = 40 GB) or just one shared read-only copy for all WPARs 40 WPAR = 1 GB).This saves man-power in maintenance, disk space AND memory (if the application is loaded in the Global AIX then there is only one copy in RAM)
- Maintenance of one Global AIX plus syncwpar command is much less work than say updating 40 copies of AIX
- Especially if you run WPAR buckets:This means instead of running say 40 LPARs you run three Global AIX LPARs for different 3 AIX 6 Technology Levels that you need - WPARs can be move between these as they are updated to high TL's. Eventually, you empty the lowest one and remove it. Then create a new Global AIX for the next new TL as it becomes available
- Application mobility much simpler to organise than LPM
- Global AIX admin can see and change ALL the filesystems of the WPARs - for example, adding a tool to /usr/local/bin is a simple "cp" command away.
- Lots of WPARs on one AIX is simpler to monitor and control than monitoring across many LPARs.
- Rapid cloning is easy and lets you use "disposable images" - simple to create, experiment and throw away
- If you mess up a WPAR, you can enter it from the Global AIX to fix it - if you mess up an LPAR it may not boot!
- Backups are much easier and smaller than a LPAR mksysb - a default WPAR is around 75 MB as a backup file. Of course, more if you have applications + data but the 2 GB of AIX does not have to be included in the backup.
Also does the AIX 5.2 in a WPAR
later this year help the customer? This is a statement of direction for AIX7 (see Link
- Remove old hardware = Quadruple Win: remove end of life slower GHz (or MHz) machines, higher electrical costs, higher maintenance costs, large foot print
- AIX 5.2 in this mode is supported
- It does get the POWER7 SMT=4 boost & the underlying robust AIX7 kernel and the electrical power saving and .....
Of course this needs POWER7 and AIX7 - what a great win:win lifeline for all these "stuck in the past with no where to go" workloads!