Creating aggregates with disks from DS2246 and DS224C shelves

[TAO1]

Hi,

I will have a HA pair that has a stack of DS224C shelves and a separate stack with DS2246 shelves - the disks are the same size/speed. The load on the cluster isn't anywhere near pushing 6Gbps. Is it permittable to mix disks from the different shelves within the same aggregate?

I guess it isn't a good idea due to potentially different EOS dates, but is there a technical reason?

Thanks,

Ty

[paul_stejskal]

There are limited transitions between 6/12 Gb/s cabling permitted. You didn't say your platform but this will generally be available on Hardware Universe (hwu.netapp.com check for your AFF/FAS platform) and there are KBs on the topic. https://kb.netapp.com/Special:Search?qid=&fpid=230&fpth=&query=mixing+shelves&type=wiki should give you a KB matching your system.

[maffo]

hi @TAO1 

yes you can mix disks from a DS224C and DS2246 in the same aggregate, as long as the disks are the same type (HDD vs SSD) and - for HDD - share the same speed.

[TAO1]

Thanks for the replies.

@maffo, is there supporting documentation to suggest that you can mix disks from a DS224C and DS2246 in the same aggregate please?

[maffo]

hi @TAO1 

please see https://kb.netapp.com/Advice_and_Troubleshooting/Data_Storage_Software/ONTAP_OS/What_is_an_aggregate

[TAO1]

Thanks @maffo , but the doc doesn't specify mixing shelves with a 6Gbps and 12Gbps backplane. Is there anything that covers this, along with perhaps the pitfalls please?

[maffo · Accepted solution]

DSS246 and DS224C are, in fact, different shelves so that article applies. ONTAP doesn't really care about the physical location of the disk when creating an aggregate but will look at disk type and speed (e.g. all SAS 10k RPMs in one aggregate, all SAS 15k RPMs in a different aggregate).

The limitation/pitfall here, as you mentioned previously, is that the connection to some disks will only be half the speed (6Gb/s vs 12Gb/s); from your own statement however, this should not be a problem since the system is not loaded anywhere enough to saturate 6Gb/s.

[TAO1]

Thanks @maffo