RHEL4 LUN problem

epoh · 11-22-2010, 09:56 AM

Ok, so I've got an older RHEL4 system (2.6.9-34.ELsmp) which I am needing to migrate off of one LUN and onto another. My plan was to simply have the storage team assign me a new LUN and to setup LVM mirroring then remove the origional LUN. My problem is with the new LUN. I had to reboot to get the system to even see it. It now shows up in /proc/scsi/scsi but there is only one new device in /dev and I cannot even open the sd* device.. I can only open the dm-* device.

Quote:

/proc/scsi/scsi:
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: LSILOGIC Model: Logical Volume Rev: 3000
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi1 Channel: 00 Id: 01 Lun: 01
Vendor: HITACHI Model: OPEN-V*2 Rev: 5009
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 01 Lun: 02
Vendor: HITACHI Model: OPEN-V*9 Rev: 5009
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi2 Channel: 00 Id: 00 Lun: 01
Vendor: HITACHI Model: OPEN-V*2 Rev: 5009
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi2 Channel: 00 Id: 00 Lun: 02
Vendor: HITACHI Model: OPEN-V*9 Rev: 5009
Type: Direct-Access ANSI SCSI revision: 03
Host: scsi3 Channel: 00 Id: 00 Lun: 00
Vendor: AMI Model: Virtual CDROM Rev: 1.00
Type: CD-ROM ANSI SCSI revision: 02
Host: scsi4 Channel: 00 Id: 00 Lun: 00
Vendor: AMI Model: Virtual Floppy Rev: 1.00
Type: Direct-Access ANSI SCSI revision: 02

As you can see, the 2 luns are showing properly on both paths.

Quote:

/dev (edited to just devices)
brw-r----- 1 root root 253, 0 Nov 21 18:57 dm-0
brw-r----- 1 root root 253, 1 Nov 21 18:57 dm-1
brw-r----- 1 root root 253, 2 Nov 21 18:57 dm-2
brw-r----- 1 root root 253, 3 Nov 21 18:57 dm-3
brw-r----- 1 root root 253, 4 Nov 21 18:57 dm-4
brw-r----- 1 root root 253, 5 Nov 21 18:57 dm-5
brw-r----- 1 root root 253, 6 Nov 21 18:57 dm-6
brw-r----- 1 root root 253, 7 Nov 21 18:57 dm-7
brw-r----- 1 root root 253, 8 Nov 21 18:57 dm-8
brw-r----- 1 root root 253, 9 Nov 21 18:57 dm-9
brw-rw---- 1 root disk 8, 0 Nov 21 18:57 sda
brw-rw---- 1 root disk 8, 1 Nov 21 18:57 sda1
brw-rw---- 1 root disk 8, 2 Nov 21 18:57 sda2
brw-rw---- 1 root disk 8, 16 Nov 21 18:57 sdb
brw-rw---- 1 root disk 8, 17 Nov 21 18:57 sdb1
brw-rw---- 1 root disk 8, 32 Nov 21 18:57 sdc
brw-rw---- 1 root disk 8, 48 Nov 21 18:57 sdd
brw-rw---- 1 root disk 8, 49 Nov 21 18:57 sdd1
brw-rw---- 1 root disk 8, 64 Nov 21 18:57 sde
brw-rw---- 1 root disk 8, 80 Nov 21 18:57 sdf

Quote:

multipath -l
mpath2 (360060e80042955000000295500000390)
[size=68 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=1][active]
\_ 1:0:1:1 sdb 8:16 [active][ready]
\_ round-robin 0 [prio=1][enabled]
\_ 2:0:0:1 sdd 8:48 [active][ready]

mpath3 (360060e80042955000000295500001292)
[size=306 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=1][active]
\_ 1:0:1:2 sdc 8:32 [active][ready]
\_ round-robin 0 [prio=1][enabled]
\_ 2:0:0:2 sde 8:64 [active][ready]

What is confusing me is the /dev/sd* devices.
/dev/sda* is local disk
/dev/sdb & /dev/sdd is the multipath copy of the local disk
/dev/sdc & /dev/sde is the origional LUN over both paths
/dev/sdf should be the new disk, but cannot be opened:

bash-3.00# fdisk /dev/sdf

Unable to open /dev/sdf

I can open /dev/dm-9:

Quote:

bash-3.00# fdisk /dev/dm-9
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

The number of cylinders for this disk is set to 39941.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): p

Disk /dev/dm-9: 328.5 GB, 328531443712 bytes
255 heads, 63 sectors/track, 39941 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System

Command (m for help):

Any suggestions??

tommylovell · 11-23-2010, 08:22 PM

Your 'cat /proc/scsi/scsi' only shows four Hitachi "Type: Direct-Access" devices, presumably your sdb, sdc, sdd and sde.

Please do a 'dmsetup ls' and supply that.

Also, does RHEL4 have the 'lsscsi' command? (I don't remember if it did.) If so please supply its output.

tommylovell · 11-24-2010, 08:42 AM

Also, the output from 'pvs', 'vgs' and 'lvs' commands would be helpful...

epoh · 11-25-2010, 08:08 AM

I'll get that for you tomorrow (yay Thanksgiving!)

The /proc/scsi/scsi file shows 6 devices though.. 2 Lun0 on scsi0 & scsi3 = onboard drive, Lun1 on scsi1 & scsi2 = origional SAN drive, Lun2 on scsi1 & scsi2 = new SAN drive.