Tag Archives: host

AIX LUNs(LUNz) presented to host?

LUNz is the logical unit number that an application client uses to communicate with, configure and determine information about an SCSI storage array and the logical units attached to it. The LUN_Z value shall be zero.

LUNz has been implemented on CLARiiON arrays to make arrays visible to the host OS and PowerPath when no LUNs are bound on that array.  When using a direct connect configuration, and there is no Navisphere Management station to talk directly to the array over IP, the LUNZ can be used as a pathway for Navisphere CLI to send Bind commands to the array.

LUNz also makes arrays visible to the host OS and PowerPath when the host’s initiators have not yet ‘logged in to the Storage Group created for the host.  Without LUNz, there would be no device on the host for Navisphere Agent to push the initiator record through to the array. This is mandatory for the host to log in to the Storage Group. Once this initiator push is done, the host will be displayed as an available host to add to the Storage Group in Navisphere Manager (Navisphere Express).

LUNz should disappear once a LUN zero is bound, or when Storage Group access has been attained.

To conclude, the LUNz devices will be shown up in following two scenarios:
1. when arraycommpath is set to 1(enabled) and host HBAs are registered and login to Clariion array, but no “Storage Group” is configured for this host.
2. when there is no LUN configured using HLU0(Host LUN0) in the host “Storage Group”.

Figure-1 Storage Group with no LUN assigned using HLU0
To resolve this LUNz issue:
1. Verify LUNz hdisk number by issue:

## lsdev -Cc disk | grep LUNZ

 

hdisk5 Available 08-08-08     EMC CLARiiON FCP LUNZ Disk

hdisk6 Available 08-08-08     EMC CLARiiON FCP LUNZ Disk

hdisk7 Available 08-08-08     EMC CLARiiON FCP LUNZ Disk

hdisk8 Available 08-08-08     EMC CLARiiON FCP LUNZ Disk

 

2. set one of the LUNs assigned to the host using HLU0.

Figure-2 Assign LUN with HLU0
3. Remove each LUNZ device with command:
#rmdev -dl hdisk5
#rmdev -dl hdisk6
#rmdev -dl hdisk7
#rmdev -dl hdisk8

4. Reconfigure devices with command cfgmgr or emc_cfgmgr

How to configure a VMware ESX / ESXi host with a QLogic HBA to boot from SAN in a CLARiiON environment

How to configure a VMware ESX / ESXi host with a QLogic HBA to boot from SAN in a CLARiiON environment

Solution:

This procedure explains how to configure the QLogic HBA to boot ESX/ESXi from SAN. The procedure involves enabling the QLogic HBA BIOS, enabling the selectable boot, and selecting the boot LUN.

Procedure:

1. While booting the server, press Ctrl+Q to enter the Fast!UTIL configuration utility.

2. Perform the appropriate action depending on the number of HBAs.

Option Description
One HBA If you have only one host bus adapter (HBA), the Fast!UTIL Options page appears. Skip to Step 3.
Multiple HBAs If you have more than one HBA, select the HBA manually.

1. In the Select Host Adapter page, use the arrow keys to position the cursor on the appropriate HBA.

2. Press Enter.

3. In the Fast!UTIL Options page, select Configuration Settings and press Enter.

4. In the Configuration Settings page, select Adapter Settings and press Enter.

5. Set the BIOS to search for SCSI devices.

a. In the Host Adapter Settings page, select Host Adapter BIOS.

b. Press Enter to toggle the value to Enabled.

c. Press Esc to exit.

6. Enable the selectable boot.

a. Select Selectable Boot Settings and press Enter.

b. In the Selectable Boot Settings page, select Selectable Boot.

c. Press Enter to toggle the value to Enabled.

7. Use the cursor keys to select the Boot Port Name entry in the list of storage processors (SPs) and press Enter to open the Select Fibre Channel Device screen.

8. Use the cursor keys to select the specific SP and press Enter.

If you are using an active-passive storage array, the selected SP must be on the preferred (active) path to the boot LUN. If you are not sure which SP is on the active path, use your storage array management software to find out. The target IDs are created by the BIOS and might change with each reboot.

9. Perform the appropriate action depending on the number of LUNs attached to the SP.

Option Description
One LUN The LUN is selected as the boot LUN. You do not need to enter the Select LUN screen.
Multiple LUNs Select LUN screen opens. Use the cursor to select the boot LUN, then press Enter.