topic Re: Extend number of lun from 8 to up in Operating System - HP-UX

Extend number of lun from 8 to up

boudraa_1 — Thu, 21 Jun 2001 13:39:21 GMT

We have two server connected on Emc array.
The problem is we can't have than 8 lun.
Well, i want to know how or if there are any Patchs to install to do that

Many thanks
N?cym

Re: Extend number of lun from 8 to up

Victor BERRIDGE — Thu, 21 Jun 2001 15:03:21 GMT

Hi,
What EMC and what type of connection ? (FC- scsi)
Giving your configuration will help us understand:box model, which OS, what interface(S)...

Regards
Victor

Re: Extend number of lun from 8 to up

Bill McNAMARA_1 — Thu, 21 Jun 2001 15:03:56 GMT

I'm not an expert on the emc, but sdisk addressing only allows 3bits for the d field of the scsi device.

Your lun8 would be represented as

t1d0

your lun16 as

t2d0

your lun24 as
t3d0

etc..

quick way to think about it.

If your emc control port has scsi id 30

hw path =
8/8.8.0.255.1.14

1*16 + 14

You lun30 is seend thru the loop id 30

8/8.8.0.30.lun30

lun30 becomes

30/8 = 3.6

3/16= 0

hw address of lun30= 0.3.6

hw address full
8/8.8.0.30.0.3.6

device file
t3d0
and c is the instance number of the bus
8/8.8.0.30.0

Its called volume set addressing.
Your emc lun 179
is
179/8 = 22 remainder 3
22/16 = 1 remainder 6

1.6.3 = lun 179

hw address = 8/8.8.0.30.1.6.3
t6d3
c is instance of 8/8.8.0.30.1

Note there is a patch for the EMC lun gap pb.
ie delete lun 4 and lun 5 6 7 8 ... is not found.

Search in the storage forum for that.

Good luck,
Bill

Re: Extend number of lun from 8 to up

A. Clay Stephenson — Thu, 21 Jun 2001 15:06:06 GMT

Sorry,

This is a SCSI limitation. Only 3 bits thus 000-111 (0-7) are all the possible LUN's per SCSI target ID.

Re: Extend number of lun from 8 to up

Bill McNAMARA_1 — Fri, 22 Jun 2001 09:01:05 GMT

Fc addressing will work around that lun limitation, make sure that you've configured the emc to vsa mode.

Bill

Re: Extend number of lun from 8 to up

Bill McNAMARA_1 — Fri, 22 Jun 2001 12:28:58 GMT

PHKL_24004 would be the latest patch if it were an hp-ux problem.

Can you create the lun on the emc ?
Is the problem just that hp-ux doesn't see it?

Can you send the o/p of your ioscan...

Later,
Bill

Re: Extend number of lun from 8 to up

MANOJ SRIVASTAVA — Fri, 22 Jun 2001 13:25:55 GMT

Hi Boudra

You cant have the 8th LUN , this is addressing limitation . SO you need the Octal Code for adressing more than 7 disks.

Manoj Srivastava