Installation guide

Installing a DECarray with a VAX 4000 System

D.2 DSSI VAXcluster Installation of a DECarray

As many as two pairs of DSSI VAXcluster conﬁgured VAX 4000 systems can be

used with a single DECarray.

A single DECarray requires connection to two DSSI adapters to support each

DSSI bus. 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 DSSI VAXcluster conﬁguration, up to six ISEs and two adapters can be

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

and up to ﬁve disk ISEs or six disk ISEs (where one disk ISE is in the system

enclosure). For further information on DSSI VAXcluster conﬁgurations, refer

to the customer hardware information kit.

A fully conﬁgured DSSI VAXcluster system could contain one of the following:

• Two TF857 magazine tape ISEs. 16 RF disk ISEs (in SF7x storage

enclosures) and and two ISEs internal to the systems enclosure.

• One TF857 magazine tape ISE. 16 RF disk ISEs (in SF7x storage

enclosures) and three ISEs internal to the systems enclosure.

• 16 RF disk ISEs (in SF7x storage enclosures) and four ISEs internal to the

systems enclosure.

Figure D–7 shows the possible DSSI VAXcluster buses.

D–16 Installing a DECarray with a VAX 4000 System