[gpfsug-discuss] Adding ESS to existing Scale Cluster

[Sanchez, Paul]

> note though you can't have GNR based vdisks (ESS/DSS-G) in the same storage pool.

At one time there was definitely a warning from IBM in the docs about not mixing big-endian and little-endian GNR in the same cluster/filesystem.   But at least since Nov 2017, IBM has published videos showing clusters containing both.  (In my opinion, they had to support this because they changed the endian-ness of the ESS from BE to LE.)  

I don't know about all ancillary components (e.g. GUI) but as for Scale itself, I can confirm that filesystems can contain NSDs which are provided by ESS(BE), ESS(LE), GSS, and DSS in all combinations, along with SAN storage based NSD servers.  We typically do rolling upgrades of GNR building blocks by adding blocks to an existing cluster, emptying and removing the existing blocks, upgrading those in isolation, then repeating with the next cluster.  As a result, we have had every combination in play at some point in time.  Care just needs to be taken with nodeclass naming and mmchconfig parameters.  (We derive the correct params for each new building block from its final config after upgrading/testing it in isolation.)

-Paul

-----Original Message-----
From: gpfsug-discuss-bounces at spectrumscale.org <gpfsug-discuss-bounces at spectrumscale.org> On Behalf Of Simon Thompson
Sent: Wednesday, April 3, 2019 12:18 PM
To: gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
Subject: Re: [gpfsug-discuss] Adding ESS to existing Scale Cluster

We have DSS-G (Lenovo equivalent) in the same cluster as other SAN/IB storage (IBM, DDN). But we don't have them in the same file-system.

In theory as a different pool it should work, note though you can't have GNR based vdisks (ESS/DSS-G) in the same storage pool.

And if you want to move to new block size or v5 variable sunblocks then you are going to have to have a new filesystem and copy data. So it depends what your endgame is really. We just did such a process and one of my colleagues is going to talk about it at the London user group in May.

Simon
________________________________________
From: gpfsug-discuss-bounces at spectrumscale.org [gpfsug-discuss-bounces at spectrumscale.org] on behalf of prasad.surampudi at theatsgroup.com [prasad.surampudi at theatsgroup.com]
Sent: 03 April 2019 17:12
To: gpfsug-discuss at spectrumscale.org
Subject: [gpfsug-discuss] Adding ESS to existing Scale Cluster

We are planning to add an ESS GL6 system to our existing Spectrum Scale cluster. Can the ESS nodes be added to existing scale cluster without changing existing cluster name? Or do we need to create a new scale cluster with ESS and import existing filesystems into the new ESS cluster?

Prasad Surampudi
Sr. Systems Engineer
The ATS Group





_______________________________________________
gpfsug-discuss mailing list
gpfsug-discuss at spectrumscale.org
http://gpfsug.org/mailman/listinfo/gpfsug-discuss