User`s guide

Conﬁguration

2.2 Mass Storage Devices

• Terminate the SCSI and DSSI buses correctly. Failure to do this can cause

a system failure or corrupt data.

• Digital recommends that you connect all SCSI and DSSI devices to the

same ac power source.

• Do not add or remove devices that are connected to the SCSI or DSSI buses

while the power is on.

• Digital does not guarantee the correct operation of a SCSI or DSSI bus

that does not use the cables supplied by Digital or is not conﬁgured in

accordance with Digital recommendations.

• The maximum number of storage devices in the system enclosure on DSSI

Bus0isthree drives only. This means you can connect at four external

mass storage devices. If the system has a second DSSI bus, (BUS 1), no

devices on Bus 1 are contained internal to the system enclosure. The

maximum number of devices connected to Bus 1 is seven devices.

• External DSSI mass storage devices are installed in either the SF series of

expansion boxes or the R400X expansion box.

2.2.4 Guidelines for the SF series of expansion boxes

• The SF series of expansion boxes houses only 3 1/2 inch form factor devices.

• A fully conﬁgured SF12 enclosure contains four disk drives.

• There is no restriction on the number of SF expansion boxes.

2.2.5 Guidelines for the R400X expansion box

• The R400X expansion box houses either 3 1/2 inch devices or 5 1/4 inch

devices.

• The R400X expansion box may contain a maxium of seven 5 1/4 inch disk

drives or, one 5 1/4 inch tape drive and six 5 1/4 inch disk drives.

• Utilizing the split-bus fashion, the R400X expansion box may contain a

maximum of fourteen 3 1/2 inch disk drives, or one 5 1/4 inch drive and

twelve 3 1/2 inch disk drives.

• The R400X expansion box may also be utilized in split-bus fashion. In

this way, the top four media slots are connected to Bus 0 and the lower

three media slots are connected to Bus 1. Refer to the R400X Expander

Installation and Maintenance Manual (EK–349AA–MG) for information on

how to conﬁgure the R400X in split-bus fashion.

Conﬁguration 2–5