[jan-jaap]

I just saw 'XFS' mentioned twice in the thread and triggered on it, that's all ;-)

Regarding the system, let me tell you about my own 4D/70 which spent years in storage when I put my hands on it:

* The PSU, a blue 2000W "shoebox" made by L&H Research made some terrible noises. It was basically screaming.
* The twin-tower enclosure has dual centrifugal blowers in the base. They are not monitored in any way. In mine one had burned out.
* The disk was basically in the same shape as OP describes: when powered up it made some bleep-bleep (head seeking) noises, spindle motor runs, but not much else happened.
* In the end the VME backplane turned out to be jumpered incorrectly causing VME bus errors during graphics initialization.

I still can't explain the backplane problem, but everything else is to be expected if a system sits abandoned for a decade or more. So I wouldn't just cross my fingers and power it on. You risk damaging things impossible to replace these days.

* First test the PSU, outside the chassis if possible. Be careful, it puts out at least 200A@5V, screwdriver-melting stuff.
* If it works correctly, fire it up inside the chassis with all cards removed. Check fan operation (they run off the -12V rail)
* The IP4 should work with nothing else (graphics, VME ethernet) in the chassis. If you complete POST you will find the NVRAM battery long expired. IP4 doesn't understand 'resetenv', you have to enter correct values for each env value manually using the serial console.
* Now you can put back the rest of the cards and hope for the best.
* You will likely have to look for a new hard disk. Don't try latest & greatest SCSI, U320 doesn't require backwards compatibility with narrow / sync SCSI. I tried a Seagate 15K.4 in a PowerSeries once -- no joy.
* If you have a QIC tape drive it's probably QIC-24, not QIC-150. (Very) old IRIX tapes are QIC-24, otherwise there's always network installation.

I have experience with older SGIs, but it took me quite a bit of time to get my 4D/70 going again...