Digital Equipment EK-SFXXS-SG-003, Руководство по обслуживанию

Страница: 43 / 224

Theory of Operation 2–19
2.4 Service Guidelines
The following sections contain the guidelines for servicing the storage
arrays and the storage enclosures.
The guidelines for servicing the DECarray are:
• Never disconnect a 42-inch, 70-inch, or 108-inch DSSI cable that is
connected to a storage enclosure, magazine tape ISE, or the DECarray
while power is on.
• Never change the DSSI node ID of a disk ISE in a storage enclosure
while power is applied to the bus.
• Never change the DSSI ID number of an adapter module in a system.
• Use only valid DSSI bus configurations.
• Never have two DSSI devices on the same DSSI bus with the same
DSSI node ID number.
• Always take the ISE that is to be serviced off-line and then power it
down.
• Always adhere to the prescribed method for taking a system down.
• Always terminate a DSSI bus in a single-system configuration, either
with a DSSI terminator or with a storage enclosure operating in
split-bus mode.
• Always cable a magazine tape ISE to the DECarray I/O panel before
cabling any storage enclosures that belong on the same DSSI bus.
• Note that 70-inch and 108-inch DSSI cables connected to the
DECarray I/O panel are connected in order (left to right) when the
DECarray has been correctly installed using the instructions in the
installation guide. This may not be so if the instructions were not
followed at the time of installation. In that case, use the color code to
determine what ISEs are on what DSSI bus.