F5 Memory Management vCMP Guest

Here are some notes to follow when trying to determine if issues with Virtual Servers on a vCMP have anything to do with not enough memory assigned to the vCMP guest.

First of all don't rely on the GUI CPU & Memory stats as they are not very accurate.

tmsh show sys cpu | head

Sys::System CPU Information

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System CPU Usage(%)  Current  Average  Max(since 10/05/17 13:54:51)

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Utilization               51       60                            72

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Sys::Host CPUs      

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also run the following command to look at pagemem

tmctl -d blade tmm/pagemem

name      used   avail
------- ------ -------

pagemem 916182 1370624

Now calculate memory utilization percentage by doing some easy math

%mem utilization = 916182/1370624 * 100 = 66.84%

anything above 60%, we should start tweaking cores to be safer.

Anything above 80% packet drops are seen and we’re in dangerous situation like 10/3.

Here is how calculation for CPU & memory assigned for a particular VCMP guest based of the VCMP host configuration.

Total CPU = number cores assigned for VCMP guest

Total Memory  = no.of cores * no.of slots assigned for VCMP guest * 2.81GB