IBM System Storage TS3310 Setup And Operator Manual page 52

The maximum distances that the library supports on a Fibre Channel link is
determined by the link speed, the type of fiber (50-micron or 62.5-micron), and the
device to which the library is attached.
If the library attaches to an HBA, refer to the distances that are supported by the
HBA. If the library attaches to a switch, the supported distances are:
v For a 50-micron cable:
v For a 62.5-micron cable:
The library uses 50-micron cables internally. Therefore, you must use a 50-micron
cable to attach to the library's port. To attach to a 62.5-micron SAN, you must
attach the 50-micron cable to an active port, such as a port on a switch.
Using Zoning to Isolate Devices and Enhance Security
For security reasons, it is important to limit the devices that a server or servers can
recognize or access. Also, some performance configurations and SAN
configurations can result in a device being seen multiple times from the same
server. For example, if you have two HBAs from the same server connected to an
Ultrium Tape Drive in the library, the drive will be detected and appear as two
logical devices. That is, there will be two special files for one physical device.
Zoning can address these issues.
Zoning allows you to partition your SAN into logical groupings of devices so that
each group is isolated from the other and can only access the devices in its own
group. Two types of zoning exist: hardware zoning and software zoning. Hardware
zoning is based on physical fabric port number. Software zoning is defined with
WWNN or WWPN. While zoning can be reconfigured without causing an outage,
some zoning configurations can become complicated. The advantage of the
library's WWNN implementation is that you can avoid the exposure of introducing
zoning errors because you do not have to change the zoning configuration if a
drive needs service or replacement.
Attention: It is recommended that tape storage devices be connected on a
separate HBA from disk storage devices to avoid potential configuration
incompatibilities.
Using Persistent Binding to Ensure SCSI ID Assignment
When a server is booted, devices are discovered and assigned SCSI target and
LUN IDs. It is possible for these SCSI assignments to change between boots. Some
operating systems do not guarantee that devices will always be allocated the same
SCSI target ID after rebooting. Also, some software depends on this association, so
you do not want it to change. The issue of SCSI ID assignment is addressed by
persistent binding.
Persistent binding is an HBA function that allows a subset of discovered targets to
be bound between a server and device. Implemented by a WWNN or WWPN,
persistent binding causes a tape drive's WWN to be bound to a specific SCSI target
ID. After a configuration has been set, it survives reboots and any hardware
configuration changes because the information is preserved. If a drive needs to be
replaced, the new drive assumes the WWNN of the old drive because the WWNN
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TS3310 Tape Library Setup and Operator Guide
– 1-Gbit link speed = up to 500 m (1640 ft)
– 2-Gbit link speed = up to 300 m (984 ft)
– 1-Gbit link speed = up to 175 m (574 ft)
– 2-Gbit link speed = up to 150 m (492 ft)