The RZ29B drives on RAID have shown problems that are 
suppossed to be fixed by upgrading to the version 0014 
firmware.
If you are experiencing drives that are being failed by the 
controller and when pulled and put back seem to function OK, 
you are probably seeing the problem
We have identical 2100 5/250 servers with 3 channel RAID 
and RZ29B drives. One system runs VMS and the other 
Digital UNIX.  We were seeing drive failures on both systems 
at least every two weeks.  The UNIX system lost no data but 
the VMS system was not so lucky.  We run RAID 5.
We have been pursuing the issue with DEC since September 
and only last week determined that it was an identified 
problem.  There are two fixes apparently, a short term fix of 
setting a bit in a mode register on the drive or the firmware 
upgrade.  
The firmware may not be officially released yet but is on the 
way.
--------------------------------------------
Todd Acheson                           Ohio University
acheson_at_oak.cats.ohiou.edu	 Computer Services
(614)593-0034                          Athens, OH 45701
Received on Mon Nov 06 1995 - 20:52:41 NZDT