Installation guide

D.1 Single-System Installation of an DECarray

As many as four single-system conﬁgured VAX 4000 systems can connect with

a single DECarray.

The single DECarray requires connection to a DSSI adapter to support the

DSSI integrated storage elements (ISEs). The VAX 4000 Model 300 provides

two embedded DSSI adapters on the KA670 CPU module and also supports up

to two KFQSA DSSI adapters installed in the system Q-bus

™

backplane. The

VAX 4000 Model 200 provides one embedded DSSI adapter on the KA660 CPU

module and also supports up to two KFQSA DSSI adapters installed in the

system Q-bus backplane.

In a single-system conﬁguration, up to seven ISEs and one adapter can be

supported on a single DSSI bus. That DSSI bus can consist of one tape ISE

and up to, six disk ISEs or up to seven disk ISEs (where one disk ISE is in the

system enclosure). For further information on single-system conﬁgurations,

refer to the customer hardware information kit.

Brieﬂy, a fully conﬁgured single-system system could contain one of the

following:

• Two TF857 magazine tape ISEs. 8 RF disk ISEs (in SF7x storage

enclosures) and no ISEs internal to the system enclosure.

• One TF857 magazine tape ISE. 20 RF disk ISEs (in SF7x storage

enclosures) and one ISEs internal to the system enclosure.

• 24 RF disk ISEs (in SF7x storage enclosures) and two ISEs internal to the

system enclosure.

Figure D–1 shows all the possible single-system DSSI buses.

Note

A single-system DSSI bus can only be connected from a VAX 4000

system to a single DECarray and then terminate in that array. No

additional expanders can be connected to that DSSI bus.

For a VAX 4000 Model 200, DSSI bus 0 connect to ports 1 on the DECarray.

The ﬁrst KFQSA adapter connects to port 2 and the second KFQSA adapter

connects to port 3.

D–2 Installing a DECarray with VAX 4000 Systems