Digital Equipment StorageWorks UltraSCSI DS-BA370 Series, User Manual

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Storage Devices
UltraSCSI RAID Enclosure 7–7
Guidelines for Replacing SBBs
This section describes the items to consider when replacing SBBs.
Prerequisites for Replacing an SBB
Replacing an SBB is a relatively simple procedure. However, there are
several things you must consider.
When an array controller initializes a device, it establishes the device’s
physical location, the device address, and the logical unit number (LUN).
Physically moving the device, changing the bus, or changing the device
address will cause the bus to become erratic.
You can use the SBB identification label to identify the device model,
logical unit number (LUN), device address, array controller bus, and other
device specific characteristics.
___________________ Caution _____________________
To protect this sensitive electronic device from electrostatic
discharge (ESD) use the following precautions—(1) Wear an
ESD wrist strap. (2) Do not touch the printed circuit board or
the backplane connector. (3) Do not lay the device on a work
surface but place it on an electrostatic mat. (4) Place the device
in an electrostatic bag for shipment.
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SBB Replacement Methods
There are three methods for replacing StorageWorks storage SBBs: hot
swap, warm swap, and cold swap. You must determine the appropriate
replacement method based on the capabilities of the array controller before
replacing a device.
___________________ Caution _____________________
The methods for replacing DIGITAL array controllers and cache
modules are device dependent. Refer to the array user’s guide or
release notes for detailed instructions.
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Hot Swap
When you perform a hot swap, power and data are present on the SBB
enclosure connector.