User's Manual

NOTE: Each LUN can be accessed through both EVA storage controllers at the same time;
however, each LUN path is optimized through one controller. To optimize performance, if the LUN
multipathing policy is Fixed, all servers must use a path to the same controller.
Specifying DiskMaxLUN
The DiskMaxLUN setting specifies the highest-numbered LUN that can be scanned by the ESX
server.
• For ESX 2.5.x, the default value is 8. If more than eight LUNs are presented, you must change
the setting to an appropriate value. To set DiskMaxLUN, select Options> Advanced Settings
in the MUI, and then enter the highest-numbered LUN.
• For ESX 3.x or ESX 4.x, the default value is set to the Max set value of 256. To set
DiskMaxLun to a different value, in Virtual Infrastructure Client, select Configuration> Advance
Settings> Disk> Disk.MaxLun, and then enter the new value.
Verifying connectivity
To verify proper configuration and connectivity to the SAN:
• For ESX 2.5.x, enter the # vmkmultipath -q command.
• For ESX 3.x, enter the # esxcfg-mpath -l command.
• For ESX 4.x, enter the # esxcfg-mpath -b command.
For each LUN, verify that the multipathing policy is set correctly and that each path is marked on.
If any paths are marked dead or are not listed, check the cable connections and perform a rescan
on the appropriate FCA. For example:
• For ESX 2.5.x, enter the # cos-rescan.sh vmhba0 command.
• For ESX 3.x or ESX 4.x, enter the # esxcfg-rescan vmhba0 command.
If paths or LUNs are still missing, see the VMware or HP documentation for troubleshooting
information.
Verifying virtual disks from the host
To verify that the host can access the virtual disks, enter the more /proc/scsi/scsi command.
The output lists all SCSI devices detected by the server. An EVA4400 LUN entry looks similar to
the following:
Host: scsi3 Channel: 00 ID: 00 Lun: 01
Vendor: HP Model: HSV300 Rev:
Type: Direct-Access ANSI SCSI revision: 02
Verifying virtual disks from the host
Use the VMware vCenter management GUI to check all devices (see Figure 25 (page 61)).
60 Configuring application servers