Specifications

Administration Guide
270 VMware, Inc.
! LUN!masking!–!With!LUN!masking,!each!LUN!is!assigned!and!accessed!by!a!
specific!list!of!connections.!Be!sure!that!LUN!masking!is!implemented!properly!
and!that!the!LUNs!are!visible!to!the!HBAs!on!ESX!Server.
! Zoning!–!Limits!access!to!specific!storage!devices!and!increases!security!and!
decreases!traffic!over!the!network.!If!you!use!zoning,!be!sure!that!zoning!on!the!
SAN!switch!is!set!up!properly!and!that!all!vmhba!and!the!controllers!of!the!disk!
array!are!in!the!same!zone.
! Storage!controller!–!If!a!disk!array!has!more!than!one!storage!controller,!make!sure!
that!the!SAN!switch!has!a!connection!to!the!controller!that!owns!the!LUNs!you!
want!to!access.!On!some!disk!arrays,!one!controller!is!“active”!and!the!other!
controller!is!“passive”!until!there!is!a
!failure.!If!you!are!connected!to!the!wrong!
controller,!you!might!not!see!the!expected!LUNs;!or!you! might!see!the!LUNs,!but!
might!get!errors!when!trying!to!access!them.
For!more!information!on!using!SANs!with!ESX!Server,!check!the!Knowledge!Base!on!
the!VMware!Web!site!at!http://kb.vmware.com/vmtnkb/supportcentral
.
Using Persistent Bindings
You!can!specify!persistent!bindings!for!your!Fibre!Channel!HBAs.!With!persistent!
binding,!ESX!Server!assigns!specific!target!IDs!to!specific!FC!SCSI!devices.!This!target!
ID!association!is!retained!from!reboot!to!reboot!unless!changed!by!you.
Persistent!binding!is!useful!if!you!are!using!raw!disks!with!ESX!Serv er.!
A!raw!disk!is!
directly!mapped!to!a!LUN!or!physical!disk!drive!on!your!storage!area!network!(SAN).!
ESX!Server!directly!accesses!the!data!on!this!disk!as!a!raw!device!(and!not!as!a!file!on!a!
VMFS!volume).
You!can!persist!bindings!through!the!VMware!Management!Interface!or!
through!the!
service!console.!For!information!on!persisting!bindings,!see!“Storage!Management”!on!
page 196.
Determining Target IDs Through the Service Console
To!use!the!service!console,!type!cat!
/proc/scsi/<FC_SCSI_driver>/<adapter_number>!to!determine!the!target!IDs.!
Example Output for an Emulex HBA
#cat /proc/scsi/<FC_SCSI_driver>/<adapter_number>
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.
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Portname: 10:00:00:00:c9:32:23:49 Nodename: 20:00:00:00:c9:32:23:49