IBM DS8700, Introduction And Planning Manual

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Note: Do not use link extenders with emulation functions on links over which
Remote Mirror and Copy operations are performed. These units introduce
additional path delay.
v
Because the Fibre Channel architecture allows any channel initiator to access any
Fibre Channel device, without access restrictions, a security exposure can occur.
Have your IBM service representative set the Fibre Channel access modes to the
proper setting. See the
IBM System Storage DS8000 Host Systems Attachment Guide
for more information about Fibre Channel access modes.
v DS8000 storage units can connect to IBM SAN Volume Controller host systems.
See the
IBM System Storage DS8000 Host Systems Attachment Guide for more
information.
Attention:
Signal loss tolerance for Fibre Channel links running at 8 Gbps are
reduced -1.4 dB as compared to links running at 4 Gbps. It is
recommended that you take necessary steps to ensure links are within
the signal loss parameters listed when planning a move from 4 Gbps
FC to 8 Gbps FC adapters with existing infrastructure. Use of more
than two patch panels or other link connectors between two 8 Gbps
ports at maximum distance of 10 km may result in greater link loss
than is acceptable. Signal loss tolerance, with measurements including
all connectors and patch panel connections, are:
v Loss per 10 km for 8 Gbps speed is -6.4 dB.
v
Loss per 10 km for 4 Gbps speed is -7.8 dB.
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Introduction and Planning Guide