topic Re: Disk hot plug? in Operating System - HP-UX

Disk hot plug?

Jose Muñoz_3 — Wed, 15 Jun 2005 18:28:50 GMT

I need his help.

I have superdome server, We need to remove a disc. We do not know which is the procedure.

we do not know if it is hotplug.

#ioscan -fnkC disk
disk 3 1/0/2/0/0.0.0 sdisk CLAIMED DEVICE HP 36.4GMAS3367NC
/dev/dsk/c2t0d0 /dev/rdsk/c2t0d0
disk 4 1/0/2/0/0.2.0 sdisk CLAIMED DEVICE HP 36.4GST336753L
C
/dev/dsk/c2t2d0 /dev/rdsk/c2t2d0

# pvdisplay -v /dev/dsk/c2t2d0
pvdisplay: Couldn't find the volume group to which
physical volume "/dev/dsk/c2t2d0" belongs.
pvdisplay: Cannot display physical volume "/dev/dsk/c2t2d0".
[factdb] / # pvdisplay -v /dev/dsk/c1t2d0
pvdisplay: Couldn't find the volume group to which
physical volume "/dev/dsk/c1t2d0" belongs.
pvdisplay: Cannot display physical volume "/dev/dsk/c1t2d0".

P/N:
Disk hot plug 286713-B22
Disk no hot plug:271832-B22
Thanks,

Re: Disk hot plug?

Mel Burslan — Wed, 15 Jun 2005 19:46:04 GMT

what is your server's model ? If you do not know, run command

# model

also if this is an internal disk or external. From the hardware path I think you are talking about internal disks.

Hot plug or not are usually associated with the type of server you have and how the disk is located inside the server.

Re: Disk hot plug?

D Block 2 — Wed, 15 Jun 2005 22:23:31 GMT

Jose,

note: Mel from our Forum did ask you to confirm.. is the DRIVE "internal" or "external".. if the drive is part of the interal root disk group..

There should be an Alarm or SCSI erros that a disk is going bad...

run: # dmesg

run: ioscan -fnC disk

this shows you the H/W Path and Special-Device:
0/4/0.2.2 /dev/dsk/c0t1d0
etc..

what disk unit do you have ? SC10

Look at the outside of the drives, and
Look at the TOP light indicators for the housing of the drives... ANY LIGHTS ?

if you think, c1t2do, is bad, then look at the LIGHT on the outside of the disk drive unit..
telnet to your server and run:

while true
do
head < /dev/rdsk/c1t2do > /dev/null
done

does the LIGHT on the drive LIGHT up, go look at the Drive and note the FAST blinking light.

============= NOTE ===================
you should mark all your INTERNAL ROOT disks with a LABEL or marker for the H/W paths.

run: ioscan -fnC disk

and mark the H/W path, example:
0/4/0/1.2.1 Drive1
0/4/0/1.3.1 Drive2

after you know the H/W path, you can then
find the associated disk path from ioscan.

Re: Disk hot plug?

Suraj Singh_1 — Wed, 15 Jun 2005 23:12:39 GMT

Hi Jose,

Just by looking at the outputs you have provided, its almost impossible to judge if the disk you are talking about is a HS (Hot Swap) or NHS (Non HS) disk.

I think you would need to look at the disk enclosure physically to judge that. Even the root disks can be HS. In fact in most of the recent servers, even the internal disks are HS disks. So i am almost certain that the disk you are talking about is also hot swap.

HTH,
Suraj

Re: Disk hot plug?

Basheer_2 — Thu, 16 Jun 2005 08:06:40 GMT

Hi Jose.
It depends on the Server. I have L-2000 (rp5450) I Put in 2 Internal disks on-line and also 3 disks to my HP Sure Store Array 12H.

use this link
http://docs.hp.com/en/index.html#Browse%20by%20Topic

then select hardware, that will give you all the info on your model.

Hope this helps
Thanks
Basheer

Re: Disk hot plug?

Jose Muñoz_3 — Thu, 16 Jun 2005 09:33:19 GMT

Thanks,
I am sorry it, I do not specify any things.

The server is Superdome 32 way.
# model
9000/800/SD32000

The disk is in HP Disk system 2110.(internal disk), the disk is SCSI 36Gb 320 15 K

The disk does not belong(concern) to any vg, The disk not being used. The disk not this one damaged, we want to install (to move) the disk in other server.
# ioscan -fnC disk|more
Class I H/W Path Driver S/W State H/W Type Description
===========================================================================
disk 0 0/0/1/0/0.0.0 sdisk CLAIMED DEVICE HP 36.4GST336753L
/dev/dsk/c0t0d0 /dev/rdsk/c0t0d0

disk 1 0/0/1/0/0.2.0 sdisk CLAIMED DEVICE HP 36.4GST336753L
/dev/dsk/c0t2d0 /dev/rdsk/c0t2d0

disk 3 1/0/2/0/0.0.0 sdisk CLAIMED DEVICE HP 36.4GMAS3367NC
/dev/dsk/c2t0d0 /dev/rdsk/c2t0d0

disk 4 1/0/2/0/0.2.0 sdisk CLAIMED DEVICE HP 36.4GST336753L
/dev/dsk/c2t2d0 /dev/rdsk/c2t2d0

# vgdisplay -v /dev/vg00|more
--- Volume groups ---
VG Name /dev/vg00
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 10
Open LV 10
Max PV 16
Cur PV 2
Act PV 2
Max PE per PV 4350
VGDA 4
PE Size (Mbytes) 8
Total PE 8680
Alloc PE 8644
Free PE 36
Total PVG 0
Total Spare PVs 0
Total Spare PVs in use 0

--- Physical volumes ---
PV Name /dev/dsk/c0t0d0
PV Status available
Total PE 4340
Free PE 18
Autoswitch On

PV Name /dev/dsk/c2t0d0
PV Status available
Total PE 4340
Free PE 18
Autoswitch On

Sr, Suraj Singh your response is correct "its almost impossible to judge if the disk you are talking about is a HS (Hot Swap) or NHS (Non HS) disk.", The server is in production, we want to avoid turn-off the server to remove the disk and see the number of part.

Re: Disk hot plug?

Mel Burslan — Thu, 16 Jun 2005 10:21:23 GMT

Jose,

Take this advice with a grain of salt, as I have never actually managed a superdome, hands-on, but knowing this architecture has redundancies built in for very high availability, I am under the impression that you can take the unused drives out, while your system is in operation. According to the ioscan and vgdisplay outputs you provided, unless there are no other volume groups present on this system, you can safely remove disk1 or disk4 as listed on the ioscan output.

to make sure you do not have any other volume groups, run command

# strings /etc/lvmtab

you should see something like
/dev/vg00
/dev/dsk/c0t0d0
/dev/dsk/c2t0d0

if you see something in addition to this, it means that you may have other volume groups, in which case you may need to check the output again to see if either one or both of the disk1 & disk4 are being used.

If you are totally unsure about hot pluggable or not situation, you may always check with one of the HP hardware support people who come on your site to service your machines. I found them to be really helpful people. A quick phone call to one of them, should ease your mind about questions.

Hope this helps.

Re: Disk hot plug?

Suraj Singh_1 — Thu, 16 Jun 2005 10:32:54 GMT

Hi Jose,

If you are talking about the disks in hp ds 2110, then your disks are hot pluggable.

http://h18006.www1.hp.com/products/storageworks/ds2110/index.html

The ds2110 has four hot pluggable slots, with individual disk capacities from 18 to 146 GB. The ds2110 capacity can exceed 500 GB with 146 GB drives.

HTH,
Suraj

Re: Disk hot plug?

Robert-Jan Goossens_1 — Thu, 16 Jun 2005 10:48:09 GMT

Yes the disk is HS.

ST336753L

http://www.seagate.com/support/disc/manuals/scsi/100148123b.pdf

chapter 5.2.6
Hot plugging Cheetah 15K.3 SCSI disc drives

Regards,
Robert-Jan

Re: Disk hot plug?

Steven E. Protter — Thu, 16 Jun 2005 10:50:24 GMT

I love this thread.

Simple rule: If it has a handle its probably hot swappable.

However, depending on your mirror configuration talking out the disk can be a disaster waiting to happen.

So long as you are sure nothing is on it, go ahead based on the high quality research of the others.

SEP

Re: Disk hot plug?

Jose Muñoz_3 — Thu, 16 Jun 2005 11:28:25 GMT

Thank you very much to all.
Mr, Suraj Singh, Thank you very much for his response, you say"If you are talking about the disks in hp ds 2110, then your disks are hot pluggable.
"http://h18006.www1.hp.com/products/storageworks/ds2110/index.html

Mr, Robert-Jan Goossens, Thank you very much for his response, you say Yes the disk is HS. ST336753L http://www.seagate.com/support/disc/manuals/scsi/100148123b.pdf
chapter 5.2.6
Hot plugging Cheetah 15K.3 SCSI disc drives

We remove Two disk and the system continue working without interruptions.

Re: Disk hot plug?

Jose Muñoz_3 — Thu, 16 Jun 2005 11:33:04 GMT

The given documents by Mr, Suraj Singh and Mr, Robert-Jan Goossens justifying the response.

"http://h18006.www1.hp.com/products/storagewhttp://www.seagate.com/support/disc/manuals/scsi/100148123b.pdf
chapter 5.2.6