Server does not find boot disk

[Vincent Farrugia]

Hello,

This is a continuation of Stefan Saliba's "Inserting disks in Jamaica".

I did a server decommisioning in which basically I removed 512Mb of memory and replaced a MUX card with an X25 card. I also replaced 10 disks with 10 other disks (18.2 with 9.1 Gb) in their Jamaica storage array. The customer told me that everything is configured in the harddisks. I took care to replace the disks in the same slot as they are supposed to reside. The D-Class server has no disk; it boots from 1 of the disks in the enclosure.

I turn on the machine and surprise surprise, no boot disk was found. I did a search for boot devices but after like 2-3 mins, only the CD-ROM, tape drive and LAN appeared. But, the harddisks of the enclosure were seen to be accessed at this time, so there is communication between the Jamaica and the D-Class. But it seems that it couldn't detect any bootable device from 10 disks.

What could be the problem? The Jamaica is connected using 2 SCSI cards, and both were lighting up green, no problem.

Many thanks for your help as ever.

Vince

[David Navarro]

Hi, Vicent. similar question, similar answer. Take a look at pins in cables. Several time, changing servers from CDP to another, we had many problems similar. That is. I unplug disks, then I plug disk in the same order, and surprise, one or many disk doesn't work. Normaly. Problem was with cables. You has a customer, then I understand you're a HP distributor... Probably you had a lot of old SCSI cables. replace it. And if that cables are from HP, pins are delicates.

For me. best option is do a search comamnd in IPL. This will show you how many disks controler can see. And if you have a disk that let light on for many seconds, this disk is having a ID conflict.

Best luck.

[Vincent Farrugia]

I thought that it's the cables as well. Then I tied them up securely using a screwdriver but the same thing happened.

I did a search in IPL and only the CDROM, tape drive and LAN were visible after a lot of seconds (minutes actually). During these minutes, the first 2, then next 2 and so on disks of the enclosure were lighting up, as if trying to access them. But no bootable devices were found surprisingly!

[David Navarro]

Hi,
You're having a SCSI ID conflict.
Problem is not if the cable is screwed or not. Problem is normally with cables pins. Unplug cables and terminator, and look at pins. Probably one of them is broken or bended.
Another idea. disks are SE or DF. Are you using the correct SCSI terminator...

[Vincent Farrugia]

Hello,

The terminators were already installed in the enclosure and I kept the same ones without ever touching them.

[David Navarro]

I don't know where the problem is. But if you disk are lighting two at time,you have a problem with SCSI ID's.
unplug one disk in each channel. and do a SEARCH. If you can see it. then try swapping disk plugged / Unplugged. And look at address.
When you have conflicts for and error setting ID's or a cable with a PIN bended. Syntoms was very unpredictable.

[Vincent Farrugia]

Hello,

Your latest answer flashed a light in my mind.

I think I made a small mistake. The D-Class server has an HSC FWD SCSI-2 card; in this case, since the enclosure is configured in split-bus mode, there are two of these cards. When I opened the server to remove memory and install X25 card, I think I connected the SCSI ribbon to both cards instead of one... could this be why there is a SCSI conflict?

If yes, I have solved the problem.

Thanks very much for your answers. Lots of points coming your way.

Vince

[David Navarro]

Hi, Vicent
I Understand, you have both controllers in the same bus?.
If this is true. your ID conflict is with ID 7 of controller.
If not, maybe one of these controlles had configured another ID diferent than 7. And is conlicting with one of disks.

Another posibility is:
When you have internal FW/SCSI card, you connect internally with internal cabinet of disks. This cabinet, has their own terminators (At the end of internal cable ). When you do that, you must remove card terminators (3 yellow chips in card). If you swap both controllers, then you will have two terminators one in card and another one in cable. That can be a problem.

Best Luck

[Vincent Farrugia]

Hello,

I connected both SCSI cards to the SCSI ribbon connected to the internal cabinet of disks, yes. Do I have to remove one of them?

[David Navarro · Accepted solution]

Yes. You must connect internal ribbon only to the card that has their terminators (Yellow chips) in hols position. The other one has terminator close to connector.

I Think that's all.