Considerations for hot-adding disk shelves with IOM12 modules
You should familiarize yourself with aspects and best practices about this procedure before hot-adding disk shelves.
General considerations
If you are hot-adding a disk shelf with IOM12 modules to an existing stack (of disk shelves with IOM12 modules), you can hot-add the disk shelf to either end, the logical first or last disk shelf, of the stack.
- A system can have multipathed and quad-pathed stacks of disk shelves with IOM12 modules.
If you have an HA pair, ONTAP shows the system configuration as
multipath HA
. If you have a single-controller configuration, ONTAP shows the system configuration asmultipath
. - This procedure assumes your configuration is using in-band ACP.
For configurations that have in-band ACP enabled, in-band ACP is automatically enabled on hot-added disk shelves. For configurations in which in-band ACP is not enabled, hot-added disk shelves operate without any ACP functionality.
- Nondisruptive stack consolidation is not supported.
You cannot use this procedure to hot-add disk shelves that were hot-removed from another stack in the same system when the system is powered on and serving data (I/O is in progress).
Best practice considerations
- The best practice is to have the current version of the Disk Qualification Package (DQP) installed before hot-adding a disk shelf.
Having the current version of the DQP installed allows your system to recognize and utilize newly qualified disk drives; therefore, avoiding system event messages about having non-current disk drive information. You also avoid the possible prevention of disk partitioning because disk drives are not recognized. The DQP also notifies you of non-current disk drive firmware.
- The best practice is to have the current versions of disk shelf (IOM) firmware and disk drive firmware on your system before adding new disk shelves, shelf FRU components, or SAS cables.
Current versions of firmware can be found on the Lenovo Support Web site.
SAS cable handling considerations
- Visually inspect the SAS port to verify the proper orientation of the connector before plugging it in.
The SAS cable connectors are keyed. When oriented correctly into a SAS port, the connector clicks into place and if the disk shelf power is on at the time, the disk shelf SAS port LNK LED illuminates green. For disk shelves, you insert a SAS cable connector with the pull tab oriented down (on the underside of the connector).
For controllers, the orientation of SAS ports can vary depending on the platform model; therefore, the correct orientation of the SAS cable connector varies.
- To prevent degraded performance, do not twist, fold, pinch, or step on the cables.
Cables have a minimum bend radius. Cable manufacturer specifications define the minimum bend radius; however, a general guideline for minimum bend radius is 10 times the cable diameter.
- Using Velcro wraps instead of tie-wraps to bundle and secure system cables allows for easier cable adjustments.