[Raion]

Suffice to say that I had an SGI Challenge that someone did a bunch of development work for and I kind of forgot about it until recently. 

The hard disk is making a lot of unhappy noises and when I try to mount it it basically has to try infinitely before the OS gives up. It's not making head crash sounds or anything like that. 

I'd like someone to try to help me recover it. I don't have the equipment or expertise to do this on SCSI. Anyone here know anybody? I will pay to recover what's on here if necessary because it would be very much an inconvenience to have to have this stuff redone

[ruckusman]

That sounds like potentially failing read head amplifiers - years ago watched a youtube video - the guy swapped out the failing read heads for those from another equivalent donor drive and got the drive back up and running.

Made it look easy because he had the insert to enable him to slide one set of heads off of the donor drive, without damage - then do the same for the rescue drive, remove them for their replacement.

Then onto the donor drive heads into the the rescue drive.

Other potential option(s) is swapping the PCB from another equivalent drive with identical firmware to see if that's the issue.

BUT of course you need a second equivalent drive in both cases.