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

 
Highlighted
Regular Advisor

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

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
6 REPLIES 6
Highlighted
Regular Advisor

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

What is your "fdisk -l" output?
Life is full of bugs
Highlighted
Honored Contributor

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

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 ?
Highlighted
Regular Advisor

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

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


Highlighted
Honored Contributor

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

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
Highlighted
Regular Advisor

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

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

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

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