Installation guide

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VMware ESX Server Administration Guide
Configuring VMFS Volumes on SANs
Be sure that only one ESX Server has access to the SAN while you are using the
VMware Management Interface to configure the SAN and format the VMFS-2
volumes. After you have finished the configuration, be sure that all partitions on the
physically shared SAN disk are set for public or shared access for access by multiple
ESX Servers (see VMFS Accessibility on page 294).
For information on configuring SANs, scanning for LUNs and setting persistent
bindings through the VMware Management Interface, see Configuring Storage Area
Networks on page 232.
Scanning for Devices and LUNs
ESX Server scans for devices, and LUNs on these devices, whenever a Fibre Channel
driver is loaded. You can manually initiate a scan through the VMware Management
Interface or by using the vmkfstools -s command.
You may want to rescan devices or LUNs whenever you add a new disk array to the
SAN or create new LUNs on a disk array. You may also want to rescan LUNs when you
change the LUN masking on a disk array.
Note: For QLogic adapters, you must do one additional step before scanning, in
order to recognize new LUNs on existing disk arrays. For each and every numeric
entries in /proc/scsi/qla2200 or /proc/scsi/qla2300, run the
appropriate command, as the root user, on the service console:
echo “scsi-qlascan” > /proc/scsi/qla2200/<numeric_entry>
or
echo “scsi-qlascan” > /proc/scsi/qla2300/<numeric_entry>
These commands tell the QLogic driver to clear its cache of existing LUNs.
Caution: Do not run the vmkfstools -s command on non-Fibre Channel
adapters.
Type the following command to scan for devices or LUNs through a particular FC SCSI
adapter:
vmkfstools -s <FC_SCSI_adapter>
For example, if you wanted to rescan SCSI adapter vmhba0 for new (and removed)
devices or LUNs, type:
vmkfstools -s vmhba0
For more information on using vmkfstools, see Using vmkfstools on page 296.