Installation guide

3.4 DSSI Basics

If you are familiar with DSSI terminology and concepts, go

to Section 3.5 and continue the installation. For additional

information on DSSI, see Table 3–4.

• VAX 6000 systems supportDSSI subsystems in single-, dual-, or tri-host

conﬁgurations, using the KFMSA adapter.

• Each KFMSA adapter has two buses, each of which can attach seven

additional nodes (ISEs or another KFMSA adapter).

• ISEs can be RF disk or TF tape devices.

• RF ISEs are housed in SF7x enclosure boxes installed either in the

system cabinet or in an SF2xx storage array cabinet.

• TF85 ISEs are housed in VAX 6000 cabinets and TF857 drive loaders

are housed in SF2xx storage array cabinets.

Table 3–4: DSSI Concepts

Term Reference Deﬁnition

DSSI Section 3.3 Digital Storage System Interconnect. A DSA-

based storage interconnect used by the KFMSA

adapter and the RF and TF series integrated stor-

age elements to transfer data and to communi-

cate with each other.

Dual-host Section 3.4.6 Storage conﬁguration where ISEs are shared be-

tween two DSSI adapters on a DSSI subsys-

tem with two host systems.

ISE Section 3.4.2 Integrated storage element. On the DSSI stor-

age bus, all RF and TF storage devices are ISEs.

KFMSA Section 3.4.1 XMI adapter for RF disks and TF tapes; enables con-

nection to these devices.

MSCP Section 3.4.2 Mass storage control protocol. An application layer pro-

tocol used by the host to perform disk I/O opera-

tions and I/O control functions.

3–8 VAX 6000 Series Installation Guide