topic Re: SAN disks not displayed (sda, sdb.. missing) in Operating System - Linux

SAN disks not displayed (sda, sdb.. missing)

Jagadesh_2 — Tue, 01 Apr 2008 14:16:25 GMT

Hi,
After adding the luns from SAN. sda, sdb.. devices are not available in /dev directory. However i can see character devices sg0, sg1.. etc.

[ dev]# cd /dev
[ dev]# ll sg*
crw-rw---- 1 root disk 21, 0 Apr 1 15:56 sg0
crw-rw---- 1 root disk 21, 1 Apr 1 15:56 sg1
crw-rw---- 1 root disk 21, 2 Apr 1 15:56 sg2
crw-rw---- 1 root disk 21, 3 Apr 1 15:56 sg3
[ dev]# ll sd*
ls: sd*: No such file or directory

# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: CX700 Rev: HP03
Type: RAID ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5671
Type: RAID ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: CX700 Rev: HP03
Type: RAID ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5671
Type: RAID ANSI SCSI revision: 03

# ./hp_rescan -a
Sending rescan signal to /proc/scsi/qla2xxx/0...
Sending rescan signal to /proc/scsi/qla2xxx/1...
Adding legacy tape devices to /proc/scsi/device_info
Scanning /proc/scsi/qla2xxx/0, target 1, LUN 0
Scanning /proc/scsi/qla2xxx/1, target 1, LUN 0

scsi0 00 00 00 DGC CX700 HP03 RAID
scsi0 00 01 00 EMC SYMMETRIX 5671 RAID
scsi0 00 00 01 DGC CX700 HP03 Direct-Access
scsi1 00 00 00 DGC CX700 HP03 RAID
scsi1 00 01 00 EMC SYMMETRIX 5671 RAID
scsi1 00 00 01 DGC CX700 HP03 Direct-Access

Please let me know how to create the sda, sdb devices and how to create emcpowera, emcpowerb accordingly from this.

Thanks

Re: SAN disks not displayed (sda, sdb.. missing)

Matthew Ghofrani — Wed, 02 Apr 2008 13:24:23 GMT

What is your "fdisk -l" output?

Re: SAN disks not displayed (sda, sdb.. missing)

skt_skt — Wed, 02 Apr 2008 14:02:27 GMT

why you r expecting them to be sda/sdb and emcpowera , emcpowerb .

what does the /proc/partitions says?
which Linux version and which Power Path version ?

Re: SAN disks not displayed (sda, sdb.. missing)

Jagadesh_2 — Thu, 03 Apr 2008 08:38:51 GMT

Details below

# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: CX700 Rev: HP03
Type: RAID ANSI SCSI revision: 04
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5671
Type: RAID ANSI SCSI revision: 03
Host: scsi1 Channel: 00 Id: 00 Lun: 00
Vendor: DGC Model: CX700 Rev: HP03
Type: RAID ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 01 Lun: 00
Vendor: EMC Model: SYMMETRIX Rev: 5671
Type: RAID ANSI SCSI revision: 03
Host: scsi0 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: CX700 Rev: HP03
Type: Direct-Access ANSI SCSI revision: 04
Host: scsi1 Channel: 00 Id: 00 Lun: 01
Vendor: DGC Model: CX700 Rev: HP03
Type: Direct-Access ANSI SCSI revision: 04

# cat /proc/partitions
major minor #blocks name

104 0 143338560 cciss/c0d0
104 1 526304 cciss/c0d0p1
104 2 49151760 cciss/c0d0p2
104 3 49151760 cciss/c0d0p3
253 0 2097152 dm-0
253 1 2097152 dm-1
253 2 2097152 dm-2
253 3 4194304 dm-3
253 4 1048576 dm-4
253 5 4194304 dm-5
253 6 10485760 dm-6
253 7 1048576 dm-7
253 8 2097152 dm-8
253 9 6291456 dm-9
253 10 1048576 dm-10

# fdisk -l

Disk /dev/cciss/c0d0: 146.7 GB, 146778685440 bytes
255 heads, 32 sectors/track, 35132 cylinders
Units = cylinders of 8160 * 512 = 4177920 bytes

Device Boot Start End Blocks Id System
/dev/cciss/c0d0p1 * 1 129 526304 83 Linux
/dev/cciss/c0d0p2 130 12176 49151760 8e Linux LVM
/dev/cciss/c0d0p3 12177 24223 49151760 8e Linux LVM

uname -a
Linux ngmlx437 2.6.9-67.0.4.ELsmp #1 SMP Fri Jan 18 05:00:00 EST 2008 x86_64 x86_64 x86_64 GNU/Linux

# cat /etc/modprobe.conf
alias eth0 bnx2
alias eth1 bnx2
alias scsi_hostadapter cciss
alias scsi_hostadapter1 qla2400
alias usb-controller ehci-hcd
alias usb-controller1 ohci-hcd
alias usb-controller2 uhci-hcd
###BEGINPP
include /etc/modprobe.conf.pp
###ENDPP

Also i am getting these messages in dmesg

Vendor: DGC Model: CX700 Rev: HP03
Type: RAID ANSI SCSI revision: 04
qla2400 0000:05:00.0: scsi(0:0:0:0): Enabled tagged queuing, queue depth 32.
scsi: host 0 channel 0 id 0 lun16384 has a LUN larger than allowed by the host adapter
scsi: host 0 channel 0 id 0 lun16385 has a LUN larger than allowed by the host adapter
scsi: unknown device type 12
Vendor: EMC Model: SYMMETRIX Rev: 5671
Type: RAID ANSI SCSI revision: 03

Re: SAN disks not displayed (sda, sdb.. missing)

skt_skt — Thu, 03 Apr 2008 09:21:43 GMT

we use following . but not using the DM but the power path. Also i suspect if u r reaching the max_luns limit. No sure what is the default limit if not specified

[/root]cat /etc/modprobe.conf
alias eth0 tg3
alias eth1 tg3
alias scsi_hostadapter qla2xxx
alias scsi_hostadapter1 ips
alias scsi_hostadapter2 ata_piix
alias scsi_hostadapter3 qla2400
alias usb-controller ehci-hcd
alias usb-controller1 uhci-hcd
options scsi_mod max_luns=256
options qla2xxx ql2xfailover=0 ConfigRequired=0
###BEGINPP
include /etc/modprobe.conf.pp
###ENDPP

Re: SAN disks not displayed (sda, sdb.. missing)

Jagadesh_2 — Thu, 03 Apr 2008 12:52:26 GMT

Installed the EMC powerpath driver to
EMCpower.LINUX-4.5.3-003 and it fixed the issue. Thanks for all your help in this.

Re: SAN disks not displayed (sda, sdb.. missing)

Jagadesh_2 — Thu, 03 Apr 2008 12:52:43 GMT

Installed the EMC powerpath driver to
EMCpower.LINUX-4.5.3-003 and it fixed the issue. Thanks for all your help in this.