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A colleague of mine contacted me during the week to ask how one could determine if a POWER7 system was capable of Active Memory Expansion. I thought I'd share my response with everyone who follows my blog.
You can check if the system is capable of providing Active Memory
Expansion (AME), from the HMC command line using the lssyscfg command, as shown here:
hscroot@hmc1:~>
lssyscfg -r sys -m Server-8233-E8B-SN1000 -F active_mem_expansion_capable
1
Alternatively you can view the capabilities of
the managed system from the HMC GUI, under System properties/Capabilities, as
shown in the following image.
Once you’ve concluded that your POWER7 system is
AME capable, the next step is to check if AME is enabled or disabled for
an LPAR. This is easily done from the AIX command line with the lparstat and/or amepat commands, as shown in the following example:
;Running
lparstat and amepat on a LPAR with AME
disabled.
$ lparstat
-i| grep Exp
Target
Memory Expansion Factor : -
Target
Memory Expansion Size : -
$
amepat | grep Expan
WARNING:
Running in no modeling mode.
Active
Memory Expansion : Disabled
;Running lparstat and amepat on a LPAR with AME enabled.
$ lparstat -i | grep -i exp
Memory Mode : Dedicated-Expanded
Target Memory Expansion Factor : 1.00
Target Memory Expansion Size : 6144 MB
$ amepat | grep -i exp
WARNING: Running in no modeling mode.
Active Memory Expansion : Enabled
Target Expanded Memory Size : 6.00 GB
Target Memory
Expansion factor : 1.00
Note
that I deliberately ran these commands as a non-root user to highlight the fact
that you don’t need root access to ascertain whether or not AME is active on an
LPAR.
By the
way, did you know that AME is now supported in SAP production environments running
on AIX and POWER7? Both SAP application servers, as well as database servers
running DB2 LUW are supported. Unfortunately there’s no support for LPARs with
Oracle RDBMS at this stage. Thanks to George Manousos from IBM Australia for
providing me with this update.
Please refer to the following SAP note.
https://www.ibm.com/developerworks/mydeveloperworks/blogs/cgaix/resource/1464605%28Power7AME%29.pdf
The SAP note also states:
Specific tests have been successfully executed with SAP ERP 6.0 (ABAP)
workload. The results of those test can be found in the following whitepaper:
ftp://ftp.software.ibm.com/common/ssi/sa/wh/n/pow03038usen/POW03038USEN.PDF
Restrictions
As AME is not recommended with large page support, AME will disable AIX
64KB pages by default.
AME monitoring capability in CCMS
Monitoring capabilities are available with saposcol v12.46 for more details see SAP note 710975.
It looks as though SAP have been quick to support AME on AIX/POWER7. This is a great benefit to SAP customers running with PowerVM on the IBM POWER platform. The following screenshot shows the SAP CCMS with AME statistics being reported.
PowerVM Integration into SAP CCMS Monitoring
expanded to include Virtualized Memory Metrics
The SAP AIX porting team continues
in further improving the integration of PowerVM into SAP system monitoring. While
in the past already most processor and AIX virtualization metrics could be
monitored via CCMS, now POWER7 Active Memory Expansion (AME) has been
included. Customers will find a new memory section in the respective
CCMS-panel as depicted in this screen shot.
For those who are not familiar with what AME actually is and how it can benefit you, I suggest you take a look at the IBM AME Wiki site first:
http://www.ibm.com/developerworks/wikis/display/WikiPtype/IBM+Active+Memory+Expansion
And watch Nigel Griffiths AME movie:
http://www.ibm.com/developerworks/wikis/display/wikiptype/movies#Movies-ame
