Specifications

VMware, Inc. 355
Chapter 12 VMware ESX Server Resource Management
This!ESX!Server!option!specifies!the!periodic!time!interval,!in!seconds,!for!automatic!
memory!reallocations.!Reallocations!are!also!triggered!by!significant!changes!in!the!
amount!of!free!memory.!The!default!is!15!seconds.
/proc/vmware/config/Mem/SamplePeriod
This!ESX!Server!option!specifies!the!periodic!time!interval,!measured!in!seconds!of!
virtual!machine!virtual!time,!over!
which!memory!activity!is!monitored!in!order!to!
estimate!working!set!sizes.!The!default!is!30!seconds.
/proc/vmware/config/Mem/IdleTax
This!ESX!Server!option!specifies!the!idle!memory!tax!rate!as!a!percentage.!A!tax!rate!of!
x!percent!means!that!up!to!x!percent!of!a!virtual!machineʹs!idle!memory!may!be!
reclaimed.!Virtual!machines!are!charged!more!for!idle!memory,!than!for!memory!that!
they!are!actively!using.!A!tax!rate!of!0!percent!defines!an!allocation!policy!that!ignores!
working!sets!and!allocates!memory!strictly! based!on!shares.!A!high!tax!rate!results!in!
an!allocation!policy!that!allows!idle!memory
!to!be!reallocated!away!from!virtual!
machines!that!are!unproductively!hoarding!it,!regardless!of!shares.!The!default!is!75!
percent.
/proc/vmware/config/Mem/ShareScanVM
This!ESX!Server!option!specifies!the!maximum!per‐virtual!machine!rate!at!which!
memory!should!be!scanned!for!transparent!page!sharing!opportunities.!The!rate!is!
specified!as!the!number!of!pages
!to!scan!per!second.!The!default!is!50!pages!per!second!
per!virtual!machine.
/proc/vmware/config/Mem/ShareScanTotal
This!ESX!Server!option!specifies!the!total!systemwide!rate!at!which!memory!should!be!
scanned!for!transparent!page!sharing!opportunities.!The!rate!is!specified!as!the!number!
of!pages!to!scan!per!second.!The!default!is!200
!pages!per!second.
/proc/vmware/config/Mem/CtlMaxPercent
This!ESX!Server!option!limits!the!maximum!amount!of!memory!that!may!be!reclaimed!
from!any!virtual!machine!using!vmmemctl,!based!on!a!percentage!of!its!maximum!size.!
Specifying!0!effectively!disables!reclamation!via!vmmemctl!for!all!virtual!machines.!
Defaults!to!50.
/proc/vmware/config/Mem/CtlMax[OSType]
These!ESX!Server!options!restrict!the
!maximum!amount!of!memory!that!may!be!
reclaimed!from!a!virtual!machine!using!vmmemctl,!based!on!the!limitations!of!guest!
operating!system!type.!The!value!is!specified!in!megabytes.!Defaults!to!128!for!
OSType=NT4!(Windows!NT!4.0),!2048!for!OSType=NT5!(Windows!2000!or!Windows!
Server!2003),!and!768!for!OSType=Linux
.