Guenadi N Jilevski's Oracle BLOG

How to discover disk name when LUN number is known (OEL5)

How to discover disk name when LUN number is known (OEL5)

I am creating 11gR2 RAC setup for one of my client. Following Oracle documentation for storage, I opted for Oracle ASM and asked storage team for new physical devices.
Storage admin thus provided me with a set of LUNs instead of actual physical device names like /dev/sdcxxx.

Now the major task is to get the actual device name associated with LUNs.
In OEL4 this is easy to get by issuing

# iscsi-ls -l
This command will give output like:

DEVICE DETAILS:

—————

LUN ID : 0

Vendor: DELL Model: MD3000i Rev: 0670

Type: Direct-Access ANSI SCSI revision: 05

page83 type3: 6001e4f0003fa9970000083c48573c94

page80: 383438303045500a

Device: /dev/sdh

LUN ID : 1

Vendor: DELL Model: MD3000i Rev: 0670

Type: Direct-Access ANSI SCSI revision: 05

page83 type3: 6001e4f0003fbc5b000008dd486dae67

page80: 383438303045500a

Device: /dev/sdl

LUN ID : 2

Vendor: DELL Model: MD3000i Rev: 0670

Type: Direct-Access ANSI SCSI revision: 05

page83 type3: 6001e4f0003fbc5b0000082048574033

page80: 383438303045500a

Device: /dev/sdp

But this command is obsolete in OEL5. The replacement for iscsi-ls in OEL5 is iscsiadm.

In OEL5, there are two ways to get the device name associated with LUN:

1. Use iscsiadm -m host -P 4

# iscsiadm -m host -P 4

It will show the output as:

************************

Attached SCSI devices:

************************

scsi6 Channel 00 Id 0 Lun: 0

Attached scsi disk sdk State: running

scsi6 Channel 00 Id 0 Lun: 1

Attached scsi disk sdm State: running

scsi6 Channel 00 Id 0 Lun: 10

Attached scsi disk sdah State: running

scsi6 Channel 00 Id 0 Lun: 11

Attached scsi disk sdai State: running

scsi6 Channel 00 Id 0 Lun: 13

Attached scsi disk sdap State: running

scsi6 Channel 00 Id 0 Lun: 14

Attached scsi disk sdaq State: running

2. Install the OEL5 package: lsscsi-0.17-3.el5 (or similar version).

# lsscsi -l

It will show the output as:

[6:0:0:22] disk DELL MD3000i 0670 /dev/sdbp

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=60

[6:0:0:24] disk DELL MD3000i 0670 /dev/sdbq

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=30

[6:0:0:31] disk DELL Universal Xport 0670 /dev/sdbx

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=60

[6:0:0:32] disk DELL MD3000i 0670 /dev/sdby

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=30

[6:0:0:33] disk DELL MD3000i 0670 /dev/sdcg

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=60

[6:0:0:71] disk DELL MD3000i 0670 /dev/sdch

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=60

[6:0:0:72] disk DELL MD3000i 0670 /dev/sdci

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=30

[6:0:0:73] disk DELL MD3000i 0670 /dev/sdck

state=running queue_depth=32 scsi_level=6 type=0 device_blocked=0 timeout=60

Here we can see the LUN numbers in begning:

[6:0:0:73] i.e 73 is the LUN number here.

[6:0:0:72] i.e 72 is the LUN number here.

Finally I created the disks with correct device names.

February 9, 2010 - Posted by gjilevski | oracle