CLAYTON@XRT.UPENN.EDU ("Clayton, Paul D.") (07/04/88)
The following question was asked regarding the changing of device unit plugs and the apparent side effects. > The other day I was rebooting my 750 when I switched the keys in the disk > packs dja1 & dja2. (RA60s) Dja1:, which normally has the 1 key in it, had > key 2 and dja2: had key 1. I figured i would let the drive with the heaviest > use on it, dja1, get some rest. When I rebooted the system, I got the errors > MOUNT/SYSTEM DJA1: ACC1 > MOUNT/SYSTEM DJA2: ACC2 > %MOUNT-F-INCVOLLABEL, incorrect volume label > -MOUNT-I-VOLIDENT, label = 'ACC2 ', owner= 'SYSTEM ',format='DECFILELIB' > %MOUNT-F-NOSUCHDEV, no such device available > lines deleted.... The item that goes into this problem is that the unit plugs on RA60, RA81 and RA82 type disks should NEVER be removed from the drive with either of the "A" or "B" channel selectors pushed IN. This is VERY important on HSC controllers, as the HSC will start talking about problems with drives with unit number of 4096 for example. Note here that the drive CAN BE left spun up, during this changing of unit numbers. In order to get the 'correct' unit back, just place the "A" and "B" buttons in the 'out' state and put the unit number plug in that you want. Then enable the "A"/"B" ports as needed. The drive will then be available as it normally would. If it does not show up, insure that the 'CONFIGURE' process is running on the system. If not, then do '$@SYS$SYSTEM:STARTUP CONFIGURE'. You should wait at least a minute before hitting the panic button. The problem you are seeing is a result of the controller not knowing what unit it is and making something up. The 'phantom' drive unit, ie. DJA242, will only 'go away' after a system reboot. The UCB blocks for the disks are unlike the UCB blocks for the LAT terminals. Disk UCB blocks will never dispappear once they are created, while the LAT UCB's will act as though they disappear. This disk UCB is no problem to VMS as any attempt to reference it will result in the error message indicating that no such device on-line. pdc Paul D. Clayton Address - CLAYTON%XRT@CIS.UPENN.EDU Disclaimer: All thoughts and statements here are my own and NOT those of my employer, and are also not based on, or contain, restricted information.