Installation guide

C H A P T E R 9 Storage and File Systems
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Note: If you are using multipathing with multiple FC HBAs, then you should run this
command on all of the FC HBAs. If, after your rescan, you see new LUNs and they have
VMFS volumes, then you will see the appropriate subdirectories when you view the
contents of the /vmfs directory.
Choosing QLogic Adapters
If you are using a QLogic storage adapter, then be sure to choose the right driver
version:
• IBM storage — QLogic driver version 6.04 (default)
• HP storage — QLogic driver version 6.04 (default)
• EMC storage — QLogic driver version 6.04 (default)
Changing VMkernel Configuration Options for SANs
In order to use all storage devices on your SAN, you may need to change some
VMkernel configuration options as described below.
To make these changes, complete the following steps.
1. Log in to the VMware Management Interface as root.
The Status Monitor page appears.
2. Click the Options tab.
3. Click Advanced Settings.
4. To change an option, click the current value, then enter the new value in the
dialog box and click OK.
For more information on changing these settings, see Changing Advanced
Settings on page 242.
Detecting All LUNs
By default, the VMkernel scans for only LUN 0 to LUN 7 for every target. If you are using
LUN numbers larger than 7 you must change the setting for the DiskMaxLUN field
from the default of 8 to the value that you need. For example, if you now have LUN
numbers 0 to 15 active, set this option to 16. Currently, an ESX Server machine can see
a maximum of 128 LUNs over all disk arrays on a SAN.
By default, the VMkernel is configured to support sparse LUNs — that is, a case where
some LUNs in the range 0 to N-1are not present, but LUN N is present. If you do not
need to use such a configuration, you can change the DiskSupportSparseLUN field to
0. This change decreases the time needed to scan for LUNs.