It seems to me that the kernel does not do the right thing when an MSCP
device goes offline and then again becomes available.  I first noticed
that when I disabled port A on my RA90 and then reenabled it (for no
particular reason whatsoever.  I was taking the system down anyways.)
The system never recovered.  I just kept getting:
raioerror
 unit available (unknown subcode) (code 4, subcode 0)
In this case it didn't matter, but ironically it ended up mattering later
on today.  I was trying to write RX50 floppies, but it seems that after I
changed floppies, the RX50 could not be accessed.  I got the same error
message.  I had to reboot between disks.

|  Boris Gjenero <bgjenero@undergrad.math.uwaterloo.ca>              |
|  Home page:  http://www.undergrad.math.uwaterloo.ca/~bgjenero/     |
|  "Luke, you're going to find that many of the truths we cling to   |
|  depend greatly on our own point of view." - Obi-Wan Kenobi, ROTJ  |