iSCSI Targets from NAS

[Atul Gautam]

Problem is regarding iSCSI target which is from NAS.

I have assigned a target to my pSeries AIX 5.3 Server. For this to work, I mentioned the target name in "/etc/iscsi/targets" file in the format ---



After that, I executed the command --
# cfgmgr -l iscsi0

I then configured iSCSI Protocol Device. Soon after performing this, I was able to see a new disk appearing.

# lspv

Then I executed the command --

# chdev -l hdiskn -a pv=yes (to assign PVID)

I also created a new volume group (newvg) and assigned this disk to it. Finally created filesystem on that disk using the command --

# crfs -v jfs -g newvg -m /test -A yes -a size= -a bf=true
# mount -a

The filesystem got mounted and was able to use it further.

BUT.......

after sometime, I see that the PV becomes inaccessible and while issuing the command --

# lsvg newvg

i get an error message.

I then restarted the server and then I couldn't even see the PV. I had to issue the command --

# cfgmgr

after which the disk appeared with no PVID assigned to it.

When I issue the command ---

# chdev -l hdisk2 -a pv=yes

it gives me an error message which is --

Method error (/usr/lib/methods/chgdisk):
0514-047 Cannot access a device.
pv

While the disks are visible ---

-bash-3.00# lspv
hdisk0 00c7f38ba17b240f rootvg active
hdisk1 00c7f38be92d85ad rootvg active
hdisk2 none None
hdisk3 none None
-bash-3.00#


After I restart the server for 4-5 times, the iSCSI LUNs become invisible or the "hdiskn" is different/other than the one which was present earlier.

Kindly suggest what steps do I need to follow and why it is happening like that.
What other points do I need to consider and how can I get my problem resolved.

OR

What is the correct way to get the iSCSI LUNs and then assign to a VG and then create a filesystem.


TIA


Atul Gautam