Show Storage Luns Allocated on Linux

February 25, 2011 | By
| 1 Reply More

Storage LUN

Hope this output helps you to trace something that you are looking for. I have pasted some of the Storage LUNs related to the output from my RHEL 5 Server. Below scsi file shows all the visible LUNs that are identified through each NIC/HBA card. This server had two Qlogic HBA card so that LUNs will be visible through both these cards. We have 6 volumes on storages; so total 12 will be visible in the scsi file.

# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 00 Lun: 02
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 00 Lun: 03
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 01 Lun: 51
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 00 Lun: 02
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 00 Lun: 03
Vendor: DGC Model: RAID 5 Rev: 0224
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 01 Lun: 51
Vendor: EMC Model: SYMMETRIX Rev: 5771
Type: Direct-Access ANSI SCSI revision: 03

Now if you go to SCSI device driver folder, you can see two files pointing to each device. For example, if you get those files you could see the visible requested LUNs.

# cat /proc/scsi/qla2xxx/1 | grep -i “total reqs”
( 0: 0): Total reqs 1701718, Pending reqs 0, flags 0×0, 1:0:81 00
( 0: 1): Total reqs 1701695, Pending reqs 0, flags 0×0, 1:0:81 00
( 0: 2): Total reqs 1701639, Pending reqs 0, flags 0×0, 1:0:81 00
( 0: 3): Total reqs 27469658, Pending reqs 0, flags 0×0, 1:0:81 00
( 1: 0): Total reqs 853521, Pending reqs 0, flags 0×0, 1:0:82 00
( 1:51): Total reqs 13804292, Pending reqs 0, flags 0×0, 1:0:82 00

 

Some Tips

As per best practice multipathing should be configured, for redundancy. Redhat default multipathing service is multipathd daemon. Below commands are from a server that has a multipathing enabled using multipathd daemon. Outputs are from the server that have two HBA cards attached to EMC storage is given below.

# multipath -ll
mpath2 (360060160a0a4120066f2443e100edc11)
[size=38 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
\_ round-robin 0 [prio=1][active]
\_ 0:0:0:2 sdc 8:32 [active][ready]
\_ round-robin 0 [enabled]
\_ 1:0:0:2 sdi 8:128 [active][ready]

mpath1 (360060160a0a41200f1c7a6af7487da11)
[size=35 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
\_ round-robin 0 [prio=1][active]
\_ 0:0:0:1 sdb 8:16 [active][ready]
\_ round-robin 0 [enabled]
\_ 1:0:0:1 sdh 8:112 [active][ready]

mpath0 (360060160a0a41200f0c7a6af7487da11)
[size=35 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
\_ round-robin 0 [prio=1][active]
\_ 0:0:0:0 sda 8:0 [active][ready]
\_ round-robin 0 [enabled]
\_ 1:0:0:0 sdg 8:96 [active][ready]

mpath5 (SEMC_____SYMMETRIX______101801D74000)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 0:0:1:51 sdf 8:80 [active][ready]
\_ 1:0:1:51 sdl 8:176 [active][ready]

mpath4 (SEMC_____SYMMETRIX______101801040000)
[size=2 MB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 0:0:1:0 sde 8:64 [active][ready]
\_ 1:0:1:0 sdk 8:160 [active][ready]

mpath3 (360060160a0a41200bca0f2230a0edc11)
[size=38 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
\_ round-robin 0 [prio=1][active]
\_ 1:0:0:3 sdj 8:144 [active][ready]
\_ round-robin 0 [enabled]
\_ 0:0:0:3 sdd 8:48 [active][ready]

Or you can install EMC Powerpath utility for multipathing, if you have two HBA cards (in the example below server is using two emulux HBA cards) connected EMC array. Its output should look similar as below.

# powermt display dev=all | more
Pseudo name=emcpowerd
CLARiiON ID=ABC00081501148 [server12]
Logical device ID=6006016022EB210024B20A1A7861DE11 [LUN 429]
state=alive; policy=CLAROpt; priority=0; queued-IOs=0
Owner: default=SP B, current=SP B Array failover mode: 1
=============================================================
—————- Host ————— – Stor – — I/O Path – — Stats —
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
=============================================================
0 lpfc sda SP B0 active alive 0 1
0 lpfc sde SP A1 active alive 0 3
2 lpfc sdi SP A0 active alive 0 0
2 lpfc sdm SP B1 active alive 0 0

Each LUN assigned to host will have unique uuid. Below example shows both native paths pointing to the same uuid (or LUN).

# scsi_id -g -u -s /block/sda
360060160a0a41200f0c7a6af7487da11
# scsi_id -g -u -s /block/sdg
360060160a0a41200f0c7a6af7487da11
#

Linux dmsetup shows mapping disks if you are using multipathd daemon.

# dmsetup ls –target=multipath
mpath2 (253, 8)
mpath1 (253, 7)
mpath0 (253, 6)
mpath5 (253, 11)
mpath4 (253, 10)
mpath3 (253, 9)

Filed Under : LINUX HOWTO, STORAGE

Tagged With : ,

Free Linux Ebook to Download

Comments (1)

Trackback URL | Comments RSS Feed

  1. Paul Martin says:

    or you could use the inq utility available from emc, much easier to read and supports more than EMC arrays

Leave a Reply

Commenting Policy:
Promotion of your products ? Comment gets deleted.
All comments are subject to moderation.