Guenadi N Jilevski's Oracle BLOG

Oracle RAC, DG, EBS, DR and HA DBA 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But this command is obsolete in OEL5.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 | oracle

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