While we're airing dirty laundry -- a couple of months ago, I mentioned to the list that we wanted to try to replace our F210's 4GB SCSI disks with 9GB disks (full shelf, no more shelves available from NetApp).
I replaced two of the 4GB disks with 9GB ones, and all was well (of course, the filer only used 4 of the 9GB, but we figured we'd dump to tape, rebuild the file system, then restore once all the drives were in place).
Bad idea. The DEC shelves and their power supply can't handle those 9GB drives, which is one reason among many that Netapp switched to the Eurologic shelves. A couple might work fine, but the drain on the power can actually bring the voltage on your write signal down low enough that your disk writes will become unreliable and eventually result in a corrupted filesystem and lost data.
Not to mention the other reasons why the F210 was limited in the size of storage it can support, which I'm sure you've heard. :)
So I'm opening the 3rd disk carrier, removing the flex circuit from the disk drive (has anyone else ever tried to do this? How the #$%! do you do it?) by prying with a screwdriver, and the screwdriver goes right through the circuit. D'oh!
I believe they have special tools you can buy for that sort of thing.
Bruce