topic Re: MSA2000 LUN Assignment in Disk Enclosures

MSA2000 LUN Assignment

Caster Troy — Thu, 09 Oct 2008 08:59:04 GMT

Hi Gurus,

I have MSA2000fc with dual controllers and 2 enclosures (1 has 12x300GB SAS disks and 2nd has 12x750GB SATA disks) plz view attachment. I dont have a SAN switch, and the MSA is directly connected to a DL580 G5 running RHEL 4 and a DL360 GThe problem is that when i map a disk to my linux server it shows me 2 disks and 2 paths (i can understand that its because multipath is not configured) but when i map another disk then it shows me only 1 path to the previous mapped disk and 1 path to the newly mapped disk and fdisk -l shows only 2 disks 1 new and 1 old, whereas i think it should show 4 disks!! plz help! also advice that how LUNs should be assigned to disks while mapping

thanks and u will get many points so dont hesitate to answer

;-)

Re: MSA2000 LUN Assignment

Uwe Zessin — Thu, 09 Oct 2008 09:03:15 GMT

Caster,
can you provide us with a picture how the servers are cable to the MSA2000fc ? Did you turn on the host interconnect ?

Re: MSA2000 LUN Assignment

Caster Troy — Thu, 09 Oct 2008 09:22:36 GMT

Hi Zessin,

Yes, the interconnect is enabled (pic 3) and the controller configuration is in pic4, the port0 of both controllers is connected to my Linux Server (not shown), and port1 of both servers is connected to my Windows Server (not shown) Sorry i cant take a pic from behind the rack.

thanx

Re: MSA2000 LUN Assignment

Uwe Zessin — Thu, 09 Oct 2008 10:44:25 GMT

I think you have an inconsistency in LUN mapping. If we go back to the first picture, SAS_V1 is mapped to LUN 0 for the first HBA and to LUN1 for the second one.

I would map a single volume to the same LUN address for all HBAs of a single server.

Just for interest, can you please etablish a command-line session to the MSA2000fc and get the output of the following two commands:
# show host-maps
# show volume-maps

put the output into a .TXT file and post as an attachment - thanks!

Re: MSA2000 LUN Assignment

Caster Troy — Thu, 09 Oct 2008 14:45:04 GMT

Zessin,

plz view attachment for output of the commands.

thankyou

Re: MSA2000 LUN Assignment

Uwe Zessin — Fri, 10 Oct 2008 16:54:43 GMT

Hello, did you make any changes between posting the attachments?

In the first screenshot, "SAS_V1_Volume1" is mapped to LUN "1" on entries "lxsrvom-fc1" + "lxsrvom-fc2".

In the 3rd attachment, the volume seems to be mapped to LUN 10
"SAS_V1_Volume1 00c0ffd5b5ec0000ecb1ec4801000000 0 >>10<< rw 0,1"
but the mapping "lxsrvom-fc2" is not listed - did you accidently abort the output for 'show host-maps'?

Re: MSA2000 LUN Assignment

Caster Troy — Sat, 11 Oct 2008 03:53:39 GMT

Hi Zessin,

No i did not make any changes, anyhow i replaced the fibre cables and restarted the whole procedure and it seems to work fine now. Thanks for all ur help fellows.
Appreciated

Re: MSA2000 LUN Assignment

Caster Troy — Sat, 11 Oct 2008 03:55:23 GMT

Reconfigured from scratch after replacing Fiber Cables