[gpfsug-discuss] dssgmkfs.mmvdisk number of NSD's

[Jonathan Buzzard]

On 01/03/2021 09:08, Luis Bolinches wrote:
> Hi
 >
> There other reasons to have more than 1. It is management of those. When 
> you have to add or remove NSDs of a FS having more than 1 makes it 
> possible to empty some space and manage those in and out. Manually but 
> possible. If you have one big NSD or even 1 per enclosure it might 
> difficult or even not possible depending the number of enclosures and FS 
> utilization.
 >
> Starting some ESS version (not DSS, cant comment on that) that I do not 
> recall but in the last 6 months, we have change the default (for those 
> that use the default) to 4 NSDs per enclosure for ESS 5000. There is no 
> impact on performance either way on ESS, we tested it. But management of 
> those on the long run should be easier.
Question how does one create a none default number of vdisks per 
enclosure then?

I tried creating a stanza file and then doing mmcrvdisk but it was not 
happy, presumably because of the "new style" recovery group management

mmcrvdisk: [E] This command is not supported by recovery groups under 
management of mmvdisk.




JAB.

-- 
Jonathan A. Buzzard                         Tel: +44141-5483420
HPC System Administrator, ARCHIE-WeSt.
University of Strathclyde, John Anderson Building, Glasgow. G4 0NG