Solved: How to cap memory on a Solaris 10 zone.

If you want to cap the usage of memory for a zone, follow below steps:-

Here we will ensure that zone(zcldvdas) doesn't use more than 3072mb memory.

# zonecfg -z zcldvdas

zonecfg:zcldvdas> add capped-memory

zonecfg:zcldvdas:capped-memory> set physical=3072m

zonecfg:zcldvdas:capped-memory> end

zonecfg:zcldvdas> verify

zonecfg:zcldvdas> commit

zonecfg:zcldvdas> exit

Now if you want to dedicate  3072mb memory to a zone so that it's always available only to this zone. Follow below steps:-

# zonecfg -z zcldvdas

zonecfg:zcldvdas> add capped-memory

zonecfg:zcldvdas:capped-memory> set locked=3072m

zonecfg:zcldvdas:capped-memory> end

zonecfg:zcldvdas> verify

zonecfg:zcldvdas> commit

zonecfg:zcldvdas> exit

You can also use a combination of physical and locked to assign max and min memory to a zone.

In the next example we are assigning maximum memory the zone can use as 3072mb while minimum 1024mb which should always be available to zone.

# zonecfg -z zcldvdas

zonecfg:zcldvdas> add capped-memory

zonecfg:zcldvdas:capped-memory> set physical=3072m

zonecfg:zcldvdas:capped-memory> set locked=1024m

zonecfg:zcldvdas:capped-memory> end

zonecfg:zcldvdas> verify

zonecfg:zcldvdas> commit

zonecfg:zcldvdas> exit

This change will be effective after reboot of the local zone.

zoneadm -z zcldvdas reboot

From Solaris10u4 onwards you can cap the memory online also using rcapadm.

rcapadm -z zcldvdas -m 3G

But remember the changes made my rcapadm are not persistent across reboot so you will still have to make the entry in zonecfg as discussed above.

You can view the set memory using rcapstat from Global Zone.

rcapstat -z 2 5

From local zone you can check this with prtconf.

prtconf -vp | grep Mem