IBM N Series - Replacing SAS Cables in a Multipath HA Configuration

Chapter 9. MetroCluster expansion cabling 135
c. Compare the firmware information in the command output with the disk shelf firmware
information at the IBM N series support site to determine the most current disk shelf
firmware version.
13.The next step depends on how current the disk shelf firmware is:
– If the firmware version in the command output is the same as or later than the most
current version on the N series Support Site, no disk shelf firmware update is needed.
Complete Steps 14 and 15.
– If the firmware version in the command output is an earlier version than the most
current version on the N series Support Site, you must update the disk shelf firmware.
Complete Steps 14 - 16.
14.Configure the system and enable licenses as needed by using the information about
configuring an HA pair in the Data ONTAP High Availability and MetroCluster
Configuration Guide for 7-Mode.
15.Boot the storage system and begin setup.
16.In Step 13, if you had an earlier version of disk shelf firmware than the most current
version on the N series Support Site, download the new disk shelf firmware file.
9.2.3 Replacing SAS cables in a multipath HA configuration
You can nondisruptively replace SAS cables in a multipath HA configuration. The SAS cables
that are described in this section include SAS copper and SAS optical cables.
When you replace SAS cables, consider the following important points:
򐂰 Replacing a SAS cable means that you are replacing a cable by using the same ports for a
controller-to-shelf or shelf-to-shelf connection.
Situations where you might want to replace a SAS cable can include when a cable fails, a
longer cable is needed, or SAS optical cables are preferred instead of SAS copper cables.
򐂰 Disk shelves that are connected with SAS optical cables require a version of disk shelf
firmware that supports SAS optical cables.
Best practice is to update all disk shelves in the storage system with the latest version of
disk shelf firmware.
򐂰 You cannot change any disks, disk shelves, or components of a controller module as part
of these procedures.
Complete the following steps to replace SAS cables:
1. Verify that your stretch MetroCluster system is Multi-Path HA by running the following
command at the console of both controllers:
sysconfig
Important: After your storage system is up and serving data, you cannot move SAS
cables (change the SAS ports to which a cable is connected) nondisruptively. If you
must correct system cabling, you can use a maintenance period to do so.
Note: Do not revert disk shelf firmware to a version that does not support SAS optical
cables.