IBM DS3500, Installation, User'S, And Maintenance Manual

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v For devices on slide rails, leave enough slack in the cables so they do not bend to a diameter of less
than 76 mm (3 in.), or a radius less than 38 mm (1.5 in.), when extended or become pinched when
retracted.
v Route the cable away from places where it can be damaged by other devices in the rack cabinet.
v Do not use plastic cable ties in place of the provided cable straps.
v
Do not overtighten the cable straps or bend the cables to a diameter of less than 76 mm (3 in.), or a
radius less than 38 mm (1.5 in.).
v
Do not put excess weight on the cable at the connection point. Be sure that the cable is well supported.
v
The following are the recommended maximum cable lengths.
– 2 Gbps: 300 m (984 ft.) of 50/125 um fiber, 150 m (492 ft.) of 62.5/125 um fiber
– 4 Gbps: 150 m (492 ft.) of 50/125 um fiber, 70 m (230 ft.) of 62.5/125 um fiber
– 8 Gbps: 50 m (164 ft.) of 50/125 um fiber, 35 m (115 ft.) of 62.5/125 um fiber
v
The following are the recommended maximum lengths of OM2 category Fibre Channel cable.
– 4 Gbps: 150 m (492 ft.) of 50/125 um fiber, 300 m (984 ft.) of 62.5/125 um fiber
– 8 Gbps: 50 m (164 ft.) of 50/125 um fiber, 150 m (492 ft.) of 62.5/125 um fiber
Installing SFP modules
The storage subsystem requires SFP modules. SFP modules convert electrical signals to optical signals
that are required for Fibre Channel transmission to and from controllers. After you install the SFP
modules, you use fiber optic cables to connect the storage subsystem to other Fibre Channel devices.
Before installing SFP modules and fiber optic cables, read the following information:
v Do not mix long-wave SFP modules and short-wave SFP modules on a single storage subsystem. Use
only short-wave SFP modules. You can use the Storage Manager Client to view the Storage Subsystem
Profile to make sure that you are not mixing long-wave and short-wave SFP modules.
Attention: Do not use long-wave SFP modules or Gigabit Interface Converters (GBICs) in any of the
Fibre Channel ports in the storage subsystem controllers. (Long-wave SFP modules and GBICs are not
supported for use in the storage subsystem or any of the attached storage enclosures. Long-wave SFP
modules and GBICs are supported only in the Fibre Channel switch ports to which the storage
subsystem connects.)
v
The SFP module housing has an integral guide key that is designed to prevent you from inserting the
SFP module incorrectly.
v
Use minimal pressure when inserting an SFP module into a Fibre Channel port. Forcing the SFP
module into a port could cause damage to the SFP module or to the port.
v
You can insert or remove the SFP module while the port is powered-on.
v
The operational or redundant loop performance is not affected when you install or remove an SFP
module.
v
You must insert the SFP module into a port before you connect the fiber optic cable.
v You must remove the fiber optic cable from the SFP module before you remove the SFP module from
the port. See “Removing SFP modules” on page 3-8 for more information.
v The speed of the SFP module determines the maximum operating speed of the Fibre Channel port in
which the SFP module is installed. For example, a 2-Gbps SFP module that is connected to a
4-Gbps-capable port will limit the speed of that port to a maximum of 2 Gbps.
Attention:
Carefully check the IBM part number, option number, and FRU part number of the SFP
module to identify its speed. There are no physical features that distinguish an 8 Gbps, 4 Gbps, or 2
Gbps SFP module from each other.
3-6
System Storage DS3500 and EXP3500: Installation, User's, and Maintenance Guide