> >   Wondering if there was a storage expansion box sold with the same foot
> > print as the 5000/2[0,4,6]0, or were the expansion units that DEC sold
> > with these machine the same box as [VAX,DEC]server 3100?
> 
> You either bought SZ12's or SZ16's with 5000/2x0's.  The SZ12 is the
> same size as the 3100's and the SZ16 is the same as the vaxstation
> 4000/90.  They were also sold with the (hot?) pluggable modular storage
> units that took the RZ2x drives - the BA-353 that sits three disks
> horizontally or the BA-350 that sits seven disks vertically and is
> rack-mountable.

    There were also different models of each shelf depending on what
"personality" board was inside. My BA-353 manual mentioned a fast
wide option board. Presumeably to match up with the faster TCDSs.
    As for hot swapping, it also depends on the shelf and the board inside.
If my memory serves me, there was a command in Ultrix that would basically
half the system, spin down the disk in question, wait for you to swap it,
and then try to resume execution and update the disk table (if you had the
proper license and software I imagine, like the PrestoServe). 
    Has anyone tried swapping a disk in a parity RAIDframe set, and have it
automatically rebuild on pmax?


    Chris