6760 ServerNet/DA Manual

Introduction to the 6760 ServerNet/DA
6760 ServerNet/DA Manual—424879-003
1-14
Fiber-Optic Cables and Connectors
Replacing SACs
If you install two 6760 adapters to control a disk module, you have additional flexibility
when you must remove either of those 6760 adapters to replace a SAC. You can
switch paths from the 6760 adapter to be removed to the other 6760 adapter so that
the system can continue to access the devices. For disks, the SAC serves the same
purpose as the 3128, 3129, and 3216 controllers used in the NonStop K-series
servers.
Before your service provider replaces a SAC on a 6760 adapter, do one of the
following:
•
If possible, change the paths that go through each SAC on that 6760 adapter to
use another 6760 adapter.
•
Stop all the devices controlled by all the SACs on that 6760 adapter.
Fiber-Optic Cables and Connectors
The fiber-optic connector on the 6761 F-SAC is smaller than the fiber-optic connector
used on NonStop K-series systems. Therefore, if you are installing disk drives or tape
drives that were formerly connected to a NonStop K-series system and if you are also
planning to use the same K-series fiber-optic cables, you must order a one-meter-long
fiber-optic adapter cable that includes a coupler for connecting the 6760 adapter cable
to the K-series cable. See Appendix A for a list of components.
Note that the length of the fiber-optic cable connection between a disk module or tape
module and its 6760 adapter cannot exceed 2 kilometers, unless you use a SCSI
extender (see Extending the SCSI Interface on page 1-14).
If your new system is not located close to your current system, you might need to order
both a coupler and 6760 adapter cable of the proper length.
SCSI Cables for Tape Drives
The SCSI cables used to connect a tape drive to a 6762 S-SAC are standard 68-pin
ultra-wide differential SCSI interface cables. See Appendix A for list of components.
Note that the length of the SCSI cable connection between a tape drive and its 6760
adapter cannot exceed 25 meters (unless a SCSI extender is used). However, the
actual cable cannot be that long because the jumper cables and internal cables use up
some of the allowed 25-meter maximum length. Therefore, the maximum cable length
usable is 23 meters (75 feet).
Extending the SCSI Interface
If the distance between a tape drive and its 6760 adapter is more than 23 meters but
less than 2 kilometers, you can connect them by using a SCSI extender. (See
Appendix A for list of components.)