Identify a disk in a vg

[Kaps_2]

Hello Everybody,

I have some 4 disk in an vg.Out of that one disk is not responding.So is there any way by which I can indentify the disk so that I will be able to take out that faulty disk.( For Example continous blinking of disk LED).

[dipesh_2]

hi

H/w path is the way to identify where the hardware is located. with vgdisplay -v will show you the physical volumes attached to that vg. if any of the disk is not responding it will show unavaillable.
with ioscan -fnCdisk command it will show no_hw at s/w status for faulty drive.



points
thx
dip

[John Waller]

My sure fire way is to run the command

dd if=/dev/rdsk/c?d?t? of=/dev/null bs=-2048
on each disk within the volume group. This will cause a contunuous access light on the disk. The once which doesn't light when you issue the command against it is more than likely the faulty one.

[TY 007]

Hello Kaps,

Run 'dd' on disk1, disk2, disk3 & disk4.

While running 'dd', check continous blinking of disk LED on Good Disk.

Identify the Bad Disk after identify the 3 Good Disks :)

Thanks

[Kaps_2]

thanks a lot john...will try..i rem the dd command but forgot the way to use that...thanks a lot for the help.

[Aneesh Mohan]

Hi,

Do vgdisplay vgname abd find out the device file of the disk and do


dd if=/dev/dsk/cxtxdx of=/dev/null bs=1024k count=1000

if dd works then you can see the green led continous blinking of the disk.


Aneesh

[tkc]

run vgdisplay of the vg to check all the 4 disk device files.
ioscan -fnC disk to confirm their hardware path. with the hardware path, you can trace the cable connecting to the 4 disks. dd command will only be able to tell you the other 3 disks. if you only have 4 disks, that will be good to try.

[Kaps_2]

Hello John,

Can you please explain me the command given by you...is there any possiblity that this command can lost my data on that disk...?

Thanks in advance...

[Aneesh Mohan]

Hi Kaps,

dd if=/dev/dsk/cxtxdx of=/dev/null bs=1024k count=1000

There won`t be any data loss issue

Aneesh

[Robert-Jan Goossens]

Hi,

No you will not loose any data, if you copy the input of a raw disk device to /dev/null.

# dd if=/dev/rdsk/cxtxdx of=/dev/null bs=1024k count=1000

Robert-Jan

[John Waller]

Hi

dd command I think stands for data dump. The if= tells the command the input file, in your case the disk. the of= is the output file or device. /dev/null is the hpux equivelant of a black hole. All the command does is read the contents of a disk in 2048k blocks and replicates the contents to /dev/null so no data is lost, but it is a sure way of making a disk light up as it's a constant stream of data being read. The count command mentioned by another contributer will limit the time the command will run. Without the count, you will need to issue a + C to terminate the dd command.

[Kaps_2]

thanks a lot john...will try n let u know...

[Kaps_2]

Hi John,

I tried using the DD command but got the follwing error.Any idea abt this...?

# dd if=/dev/dsk/c1t4d0 of=/dev/null bs=2048
/dev/dsk/c1t4d0: Device busy
dd: cannot open /dev/dsk/c1t4d0

Thanks,

[Aneesh Mohan]

Hi,

If you don`t have more disks then better to do dd on other disks and physically sort it out faulty one ...if you are adding count option along with dd it will not take much time.


Thanks ,

Aneesh

[Robert-Jan Goossens]

You (could) have found your dead disk, if the light on the disk is still burning, use the dd command on the other disks to exculde.

[Kaps_2]

Hi Robert,

You mean to say that I need to run dd command on othere disk n exclude the faulty disk.which will burn LED's of good disk so that I can take out the bad disk...?

[Robert-Jan Goossens]

Kaps,

I meant to say run dd on the good disk to be sure you remove the faulty disk.

The first dd gave you obviously a faulty disk and if you sure of the location, remove it.

Normally I would expect a faulty disk to turn red or give no led status at all. But I have seen faulty disks with a green led status.

Hope I expressed myself better this time :-)

Robert-Jan

[Torsten.]

If the disk is dead, the "dd" won't help you.

If you post a "ioscan -fn" and give information about the disk chassis model, we could try to help you finding the disk.

The disk has SCSI ID 4 as far as I can see...

[Kaps_2]

Hi Torsten,

Find below the output of ioscan -fn.




# ioscan -fn
Class I H/W Path Driver S/W State H/W Type Description
========================================================================
bc 0 root CLAIMED BUS_NEXUS
bc 1 8 ccio CLAIMED BUS_NEXUS I/O Adapter
graphics 0 8/8 graph3 CLAIMED INTERFACE Graphics
ext_bus 0 8/12 c720 CLAIMED INTERFACE GSC add-on Fast/Wide SCSI Interface
target 0 8/12.7 tgt CLAIMED DEVICE
ctl 0 8/12.7.0 sctl CLAIMED DEVICE Initiator
/dev/rscsi/c0t7d0
bc 2 10 ccio CLAIMED BUS_NEXUS I/O Adapter
ext_bus 1 10/0 c720 CLAIMED INTERFACE GSC built-in Fast/Wide SCSI Interface
target 1 10/0.3 tgt CLAIMED DEVICE
disk 0 10/0.3.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t3d0 /dev/rdsk/c1t3d0
target 2 10/0.4 tgt CLAIMED DEVICE
disk 1 10/0.4.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t4d0 /dev/rdsk/c1t4d0
target 3 10/0.5 tgt CLAIMED DEVICE
disk 2 10/0.5.0 sdisk CLAIMED DEVICE SEAGATE ST136475LC
/dev/dsk/c1t5d0 /dev/rdsk/c1t5d0
target 4 10/0.6 tgt CLAIMED DEVICE
disk 3 10/0.6.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t6d0 /dev/rdsk/c1t6d0
target 5 10/0.7 tgt CLAIMED DEVICE
ctl 1 10/0.7.0 sctl CLAIMED DEVICE Initiator
/dev/rscsi/c1t7d0
target 6 10/0.8 tgt CLAIMED DEVICE
disk 4 10/0.8.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t8d0 /dev/rdsk/c1t8d0
target 7 10/0.9 tgt CLAIMED DEVICE
disk 5 10/0.9.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t9d0 /dev/rdsk/c1t9d0
bc 3 10/4 bc CLAIMED BUS_NEXUS Bus Converter
tty 0 10/4/0 mux2 CLAIMED INTERFACE MUX
/dev/diag/mux0 /dev/diag/tty0p7 /dev/tty0p1
/dev/diag/tty0p0 /dev/mux0 /dev/tty0p7
/dev/diag/tty0p1 /dev/tty0p0
ext_bus 2 10/4/8 scsi1 CLAIMED INTERFACE HP 28655A - SE SCSI ID=0
target 8 10/4/8.6 target CLAIMED DEVICE
tape 0 10/4/8.6.0 tape2 CLAIMED DEVICE HP C1537A
/dev/diag/rmt/c2t6d0 /dev/rmt/c2t6d0BEST
/dev/rmt/0m /dev/rmt/c2t6d0BESTb
/dev/rmt/0mb /dev/rmt/c2t6d0BESTn
/dev/rmt/0mn /dev/rmt/c2t6d0BESTnb
/dev/rmt/0mnb
spt 0 10/4/8.6.1 spt CLAIMED DEVICE HP C1557A
/dev/rscsi/spt0 /dev/spt/dds
ext_bus 3 10/4/9 lpr2 CLAIMED INTERFACE HP 28655A - Parallel Interface
/dev/c3t0d0_lp /dev/diag/c3t0d0_lp
ext_bus 4 10/8 c720 CLAIMED INTERFACE GSC add-on Fast/Wide SCSI Interface
target 9 10/8.7 tgt CLAIMED DEVICE
ctl 2 10/8.7.0 sctl CLAIMED DEVICE Initiator
/dev/rscsi/c4t7d0
ba 0 10/12 bus_adapter CLAIMED BUS_NEXUS Core I/O Adapter
ext_bus 6 10/12/0 CentIf CLAIMED INTERFACE Built-in Parallel Interface
/dev/c6t0d0_lp
ext_bus 5 10/12/5 c720 CLAIMED INTERFACE Built-in SCSI
target 10 10/12/5.2 tgt CLAIMED DEVICE
disk 6 10/12/5.2.0 sdisk CLAIMED DEVICE HP DVD-ROM 6x/32x
/dev/dsk/c5t2d0 /dev/rdsk/c5t2d0
/dev/dsk/disk_query
target 11 10/12/5.7 tgt CLAIMED DEVICE
ctl 3 10/12/5.7.0 sctl CLAIMED DEVICE Initiator
/dev/rscsi/c5t7d0
lan 0 10/12/6 lan2 CLAIMED INTERFACE Built-in LAN
/dev/diag/lan0 /dev/ether0
ps2 0 10/12/7 ps2 CLAIMED INTERFACE Built-in Keyboard/Mouse
/dev/ps2_0 /dev/ps2kbd
/dev/ps2_1 /dev/ps2mouse
bc 4 10/16 bc CLAIMED BUS_NEXUS Bus Converter
processor 0 32 processor CLAIMED PROCESSOR Processor
processor 1 34 processor CLAIMED PROCESSOR Processor
memory 0 49 memory CLAIMED MEMORY Memory
#

[Torsten.]

Is this a K- or D-class server?

disk 1 10/0.4.0 sdisk CLAIMED DEVICE SEAGATE ST318275LC
/dev/dsk/c1t4d0 /dev/rdsk/c1t4d0

This is your disk in question.

Is there an external chassis?
I think there is, because you have 6 disks.

Now it depends what server and disk chassis you have.

[Kaps_2]

Hi Tortsen,

This is an K class server and we have an external chassis.

[Torsten.]

It's a bit hard to ask you for a bit more detailed info each time, but anyway.


Most likely the disk c1t4d0 is one of the internal disks.

Shutdown the server, take out the disk carrier and carefully watch the jumpers.

If you find the disk jumpered to SCSI ID 4, this is yours.