What's Quad-path used for?

[River]

Hi All :

I am install FAS9000, is there any know what's Quad-path  used for? Only more safety?  Should I cable as Quad-path  right now?

I study the document "Installation and Cabling Guide for DS460C, DS224C, and DS212C" but only got cable rules and got no answer to use Quad-path HA cabling.

[hariprak]

Hi,

Hope this helps https://library.netapp.com/ecm/ecm_download_file/ECMLP2485106

Thanks

[ShivaR]

Earlier SAS connectivity from shelf to controller used to have multipath which has 4 paths. Now it is an optional you can connect quad-path which means 8 paths from controllers to shelfs.

[andris · Accepted solution]

Hi River,

While quad-path HA provides additional path resiliency, the main purpose for the additional cabling is to double the I/O bandwidth to the SAS3 storage stack.

Configuring the storage stack with quad-path HA and double-wide intrastack connections is optional.  All-SSD storage stacks can benefit from the increased bandwidth, especially for

for large block (e.g. 64KB) sequential read streaming workloads.

[River]

Hi Andris:

Thanks for your answer.

I just think in the same way, as take AFF700 document as reference, Quad-path should be use in AFF solutions just in case of bandwith bottleneck.

[andris]

Sure... If you don't want to peruse performance graphs/counters (e.g. via OnCommand Performance Manager) to check the storage utilization percentage or worry about specific workloads, going with Quad-Path cabling for AFF storage is a great rule of thumb.  There's just the minor extra costs of using extra HBA ports and cables.