bad disk, need to install a new disk but...

[James Ellis_1]

I cannot find the disk! Worked with HP to verify that I had a bad disk. The diskinfo shown (size: 0 ) so I need to get another disk. Called HW support (not HP HW), they came and I shutdown the server etc. Here is what I want to ask you all experts.

My ioscan shows three Segate disks, but in the server there is only one disk. This is in the back of the N-class 9000 server, where you have to open this small door and see the hard disks. I presume the disks are not inside of the server box where you have to delve in the box?

We have EMC storage and Disk Array. I verified with EMC and they said this was not one of their disks, although EMC can host a Segate disk.

Where can this disk be? If it was already removed, should ioscan not show the disk?

To recap, I noticed problems with this disk when I tried to run a make_recovery tape, and the error shows

"vgdisplay: warning: couldn't query physical volume /dev/dsk/c7t15d0"

What I want to know is, is this disk inside the server box where we got to take off components to access the disk, or is it directly on the back of the server, where you only have to remove a small door to get to this drive. Are there any more places in the server box that a disk can be attached to?

Attached is the ioscan disk of the server, if you need to look at it.

Thanks.

[Pete Randall · Accepted solution]

James,

Your ioscan output shows two more Seagate disks on channel 1/12. You must have an I/O card in slot 7 (bottom right on the back of the N class). Follow the cable plugged into this card and you should find some sort of external enclosure containing your other two Seagate drives.


Pete

[James Specht]

First off find the hardward path to the bus for c7. You can do a full ioscan of your disks with 'ioscan -fnC disk'.

HP can give you the location of the dist once you have the hardware path. You might figure it out if other devices our on the save chain. Also your bad disk will be set to scsi address 15.

[A. Clay Stephenson]

I don't have a N-box so I can't answer in detail but the answer would still depend upon several factors -- like which kind of external disk enclosure you have. However, the method to determining your disk is still the same.

Note the ioscan section that references /dev/dsk/c7t15d0:

disk 4 1/12/0/0.13.0 sdisk CLAIMED DEVICE SEAGATE ST118273WC
/dev/dsk/c7t13d0 /dev/rdsk/c7t13d0
disk 5 1/12/0/0.15.0 sdisk CLAIMED DEVICE SEAGATE ST118273WC
/dev/dsk/c7t15d0 /dev/rdsk/c7t15d0


Pay attention to the hardware path 1/12/0/; that will correspond to a slot in the N-box that hold the SCSI controller. The hardware path to physical slot documentation is usually on the cover labers or Owner's manual. You then simply follow the cable from that controller to your disk. Note that both SCSI ID 13 and 15 are on the same bus. They will differ by DIP switch settings, jumpers, ... to set the SCSI ID on the disk itself.

[Steven E. Protter]

First, lets identify the actual hardware path of the disk that died.

Then maybe we'll know where to look.

Assuming you have not modified /etc/lvmtab, the attached utility will identify the hardware path to look at, which it seems based on the ioscan is local.

Run it, but change the email address for the output to a local address.

It's probably right next to one of the disks that will show up on the ioscan -fnC disk

SEP

[James Ellis_1]

Pete,

I did this, followed the cable coming from slot 7 and the cable lead to the storage enclosure. Wetook one of the disk out of the storage enclosures last night, and they were labeled as HP, they looked like HP disks from the front panel of the disks. We did not check all of the disks though, but on the front panel they look like HP disks.

This is a Segate disk. We took out one segate disk that was in the middle of the back of the HP CPU box, and it is labeled Segate on this disk.

Any disk from the enclosure did not look like anything like a Segate. I can check again tonight, but am pretty sure that the HP Storage Enclosure does not contain any Segate disks.

This is becoming interesting!

Thanks.

[A. Clay Stephenson]

After check the N-class documentation, slot 7 is definitely 0/12/0 so you are on the right track. If you followed that cable to the external enclosure then the drive has to be in it. Note that HP uses Seagate drives so that even if ioscan is reporting a Seagate drive it could be (and almost certainly is) an HP drive OEM'ed by Seagate. You now simply need to determine which of the drive on bus c7 is SCSI IS 15. If nothing else, pull a drive, and see which one disappears although in general you can determine the setting by looking at the switches on the back of the enclosure. In a few cases, the SCSI ID is determined solely by the physical slot in the enclosure but that is quite rare these days.

[Pete Randall]

James,

As Clay says, you're on the right track - just because it says HP on the outside doesn't mean a thing. The other thing you could try is to run a dd against one of the two drives in this enclosure to see if you can spot the activity light blinking ( dd if=/dev/rdsk/c7t13d0 of=/dev/null bs=1024k ). Obviously you try that against the function disk and if you spot the light then the other one is the failed disk.


Pete

[James Ellis_1]

Clay and Pete,

Did you mean 1/12/0 is definitely slot 7? You mention 0/12/0 as being slot 7. I think you did a typo, did you?

Thanks.

[Pete Randall]

James,

I think Clay's reference to 0/12 was a typo.

On my N-class, 1/12 is definitely slot 7 - there's a label right next to the slot which identifies the path. You can double-check the label to be sure.


Pete