vSphere Storage - ESXi 5.1 - Documentation - VMware
vSphere Storage - ESXi 5.1 - Documentation - VMware
vSphere Storage - ESXi 5.1 - Documentation - VMware
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>vSphere</strong> <strong>Storage</strong><br />
Setting LUN Allocations<br />
This topic provides general information about how to allocate LUNs when your <strong>ESXi</strong> works in conjunction<br />
with SAN.<br />
When you set LUN allocations, be aware of the following points:<br />
<strong>Storage</strong> provisioning To ensure that the <strong>ESXi</strong> system recognizes the LUNs at startup time, provision<br />
all LUNs to the appropriate HBAs before you connect the SAN to the <strong>ESXi</strong><br />
system.<br />
vMotion and <strong>VMware</strong><br />
DRS<br />
Active-active compared<br />
to active-passive arrays<br />
Setting Fibre Channel HBAs<br />
<strong>VMware</strong> recommends that you provision all LUNs to all <strong>ESXi</strong> HBAs at the same<br />
time. HBA failover works only if all HBAs see the same LUNs.<br />
For LUNs that will be shared among multiple hosts, make sure that LUN IDs<br />
are consistent across all hosts. For example, LUN 5 should be mapped to host<br />
1, host 2, and host 3 as LUN 5.<br />
When you use vCenter Server and vMotion or DRS, make sure that the LUNs<br />
for the virtual machines are provisioned to all <strong>ESXi</strong> hosts. This provides the<br />
most ability to move virtual machines.<br />
When you use vMotion or DRS with an active-passive SAN storage device,<br />
make sure that all <strong>ESXi</strong> systems have consistent paths to all storage processors.<br />
Not doing so can cause path thrashing when a vMotion migration occurs.<br />
For active-passive storage arrays not listed in <strong>Storage</strong>/SAN Compatibility,<br />
<strong>VMware</strong> does not support storage port failover. In those cases, you must<br />
connect the server to the active port on the storage array. This configuration<br />
ensures that the LUNs are presented to the <strong>ESXi</strong> host.<br />
Typically, FC HBAs that you use on your <strong>ESXi</strong> host work correctly with the default configuration settings.<br />
You should follow the configuration guidelines provided by your storage array vendor. During FC HBA setup,<br />
consider the following issues.<br />
n Do not mix FC HBAs from different vendors in a single host. Having different models of the same HBA<br />
is supported, but a single LUN cannot be accessed through two different HBA types, only through the<br />
same type.<br />
n Ensure that the firmware level on each HBA is the same.<br />
n Set the timeout value for detecting a failover. To ensure optimal performance, do not change the default<br />
value.<br />
n <strong>ESXi</strong> supports 16GB FC HBAs, but there is no support for full end-to-end 16GB connectivity from the host<br />
to array. If you use 16GB FC HBAs running at 16GB, to get full bandwidth, create at lease two 8GB<br />
connections from the switch to the storage array.<br />
Installation and Setup Steps<br />
This topic provides an overview of installation and setup steps that you need to follow when configuring your<br />
SAN environment to work with <strong>ESXi</strong>.<br />
Follow these steps to configure your <strong>ESXi</strong> SAN environment.<br />
1 Design your SAN if it is not already configured. Most existing SANs require only minor modification to<br />
work with <strong>ESXi</strong>.<br />
40 <strong>VMware</strong>, Inc.