IBM N Series, Hardware Manual

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Chapter 9. MetroCluster expansion cabling
137
The output should be the same as Step 1; the system should be Multi-Path HA, and the
SAS port and attached disk shelf information should be the same.
If the output is something other than Multi-Path HA, you must identify the cabling error,
correct it, and run the sysconfig command again.
c. Repeat steps a and b for Side B.
The Side B cables are the cables that are connected to IOM B of each disk shelf.
9.2.4 Hot-adding an SAS disk shelf by using SAS optical cables
You can hot-add an SAS disk shelf to an existing stack of SAS disk shelves or to an SAS HBA
or onboard SAS port on the controller (as a new stack). Hot-adding a disk shelf involves
installing, cabling, and verifying the disk drive and disk shelf firmware versions.
Before you begin, verify that the following prerequisites are met:
򐂰 You must verify that your storage system meets the requirements for the disk shelf (and
disk drives) that you are hot-adding.
򐂰 You ordered and received the appropriate type, number, and length of SAS optical cables
that are required for your configuration.
򐂰 You met the following requirements if you are hot-adding a single disk shelf or a stack of
disk shelves directly to a system controller:
– Each controller in your storage system must have enough available PCI SAS HBA or
onboard SAS ports.
– You must complete the “Completing the SAS cabling worksheet” so that you know how
to cable your disk shelf or stack of shelves to the controller.
򐂰 If you are hot-adding a disk shelf with SAS optical cables to a stack of disk shelves that is
connected with SAS copper cables, you can temporarily have both cable types present in
the stack.
After the disk shelf is hot-added, you must replace the SAS copper cables for the rest of
the shelf-to-shelf connections in the stack and the shelf-to-controller connections from the
first and last disk shelf in the stack so that the stack meets the cabling rules for using SAS
optical and SAS copper cables. This means that you must order the appropriate number of
SAS optical cables.
Complete the following tasks to add a different disk cable:
򐂰
If you need to, you can use longer cables to connect the hot-added shelf.
This is a cable replacement and for Multipath HA systems can be done nondisruptively.
򐂰
If you are hot-adding a disk shelf to an existing stack, this procedure is written for
hot-adding the disk shelf to the logical last disk shelf of the stack.
򐂰 If you are hot-adding more than one disk shelf, hot-add one at a time.
򐂰 If you are installing the disk shelf in an equipment rack or NetApp cabinet, you must install
the two-post telco tray kit or four-post rail kit that came with your disk shelf.
Installing a disk shelf for a hot-add
Installing the new SAS disk shelf involves securing the disk shelf in a rack by using the
applicable two-post telco tray kit or the four-post rail kit and setting the disk shelf ID.
Note: Cables can be replaced nondisruptively in multipath HA configurations.