Specifications

VMware, Inc. 329
Chapter 12 VMware ESX Server Resource Management
Improving Performance
Before!deploying!all!your!virtual!machines,!we!suggest!that!you!create!a!list!of!all!the!
virtual!machines!you!plan!to!run!on!ESX!Server.!For!each!virtual!machine,!identify!its!
primary!functions!and!applications.!Based!on!its!primary!function,!determine!its!
limiting!resources.!For!example,!a!Web!server’s!most!limiting
!resource!may!be!memory,!
while!a!terminal!services!server’s!most!limiting!resource!may!be!CPU.!Similarly,!a!
database!server’s!most!limiting!resource!may!be!disk!bandwidth.
In!this!section,!we!provide!some!general!guidelines!on!improving!performance!on!
‘VMware!ESX!Server.!However,!some!of!these!guidelines!may!not!be!appropriate!for
!
you,!depending! on!your!particular!workplace!situation.
For!example,!you!might!want!to!give!more!memory!shares!and!a!higher!memory!
minimum!to!a!virtual!machine!Web!server!for!Platinum!customers,!compared!to!a!
virtual!machine!Web!server!for!Silver!customers!or!for!an!internal!Web!server.
Improving Slow Performance
If!performance!seems!slow,!determine!whether!the!slow!performance!applies!to!all!
virtual!machines!on!an!ESX!Server!or!to!just!one!virtual!machine.!
Improving Slow Performance on ESX Server
If!you!notice!slow!performance!on!all!your!virtual!machines,!examine!CPU!usage.!
Determine!how!much!idle!time!each!processor!has.!Check!overall!system!CPU!
utilization!through!the!VMware!Management!Interface.!If!the!processors!are!not!taxed,!
and!total!system!CPU!utilization!is!under!80%,!the!problem!is!probably!not!CPU
!usage.!
If!CPU!resources!are!not!the!problem,!check!whether!the!VMkernel!is!swapping!out!
memory.!Check!the!output!of!/proc/vmware/sched/mem!from!the!procfs!interface!in!
the!service!console.!For!more!information,!see!“Service!Console!Commands”!on!
page 353.
N
OTE Determine!which!virtual!machines!are!more!important!and!which!ones!will!benefit!
from!additional!resources.!You!do!not!need!to!optimize!each!resource!for!each!virtual!
machine.
NOTE If!you!run!several!virtual!machines!with!similar!guest!operating!systems!on!ESX!Server,!
you!will!have!a!higher!overcommitment!of!memory,!without!noticing!a!performance!
degradation!in!ESX!Server.!In!general,!similar!guest!operating!systems!enable!greater!
memory!sharing!in!virtual!machines.!See!“Managing!Virtual!Machine!Memory”!on!
page 351