NetApp AFF A700, System Documentation

Page: 1552 / 1672

If you need to install an additional PCI SAS HBA, the best practice is to use 12Gb SAS
HBAs to keep controller-to-stack connectivity at 12Gbs for maximum performance.
Using 6Gb SAS HBAs or a combination of 6Gb SAS HBAs and 12Gb SAS HBAs is
supported; however, IOM12 module connections to 6Gb SAS HBAs are negotiated down to
6Gbs, resulting in lower performance.
• Your system cannot have any SAS cabling error messages.
Download and run Config Advisor to verify that your SAS connections are cabled correctly.
You must correct any cabling errors using the corrective actions provided by the error messages.
NetApp Downloads: Config Advisor
Using mini-SAS HD SAS optical cables
• If you are using mini-SAS HD SAS optical cables or a mix of mini-SAS HD SAS optical cables and SAS
copper cables in the stack of disk shelves, you must have met the rules in Mini-SAS HD SAS optical cable
rules .
• If you are hot-adding a disk shelf with mini-SAS HD SAS optical cables to a stack of disk shelves that is
connected with SAS copper cables, you can temporarily have both cable types in the stack.
After hot-adding the disk shelf, you must replace the SAS copper cables for the rest of the shelf-to-shelf
connections in the stack and the controller-to-stack connections so that the stack meets the rules in
Mini-
SAS HD SAS optical cable rules . This means that you must have ordered the appropriate number of mini-
SAS HD SAS optical cables.
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.
For single-path HA and single-path configurations, as applicable to AFF A200, AFF A220, FAS2600 series,
and FAS2700 systems, you hot-add disk shelves to the end of the stack that does not have controller
connections.
• Disk shelves with IOM12 modules must be in their own unique stack; they cannot be added to a stack that
has shelves with IOM6 modules or IOM3 modules.
This procedure does not address mixing a stack: hot-adding a shelf with IOM12 modules to a stack of
shelves with IOM6 modules.
• 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 as “multipath”.
1549