Re: Poor performance on a server-class system vs. desktop

[Ewen Chan <alpha754293@xxxxxxxxxxx>]

Silly question to all though -

Akin to the problems that Linus Tech Tips experienced with ZFS and a multi-disk NVMe SSD array -- is GlusterFS written so that it takes how NVMe SSDS operate in mind?

(i.e. that the code itself might have wait and/or wait for synchronous commands to finish first before executing the next command?)

cf. https://forum.level1techs.com/t/fixing-slow-nvme-raid-performance-on-epyc/151909

Fixing Slow NVMe Raid Performance on Epyc Linus had this weird problem where, when we built his array, the NVMe performance wasn’t that great. It was very slow – trash, basically. This was a 24-drive NVMe array. These error messages arent too serious, normally, but are a sign of a missed interrupt. There is some traffic I’m aware of on the LKML that there are (maybe) some latent bugs around the NVMe driver, so as a fallback it’ll poll the device if something takes unusually long. This many polling events, though, means the perf is ... forum.level1techs.com

I'm not a programmer nor a developer, so I don't really understand programming software, but I am just wondering that if this might be a similar issue with GlusterFS as it is with ZFS with NVMe storage devices because the underlying code/system was written with mechanically rotating disks in mind and/or, at best, SATA 3.0 6 Gbps SSDs in mind, as opposed to NVMe SSDs.

Could this be a possible reason/cause, ad simile?

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From: gluster-users-bounces@xxxxxxxxxxx <gluster-users-bounces@xxxxxxxxxxx> on behalf of Dmitry Antipov <dmantipov@xxxxxxxxx>
Sent: November 26, 2020 8:36 AM
To: gluster-users@xxxxxxxxxxx List <gluster-users@xxxxxxxxxxx>
Subject: Re: Poor performance on a server-class system vs. desktop

 

To whom it may be interesting, this paper says that ~80K IOPS (4K random writes) is real:

https://archive.fosdem.org/2018/schedule/event/optimizing_sds/attachments/slides/2300/export/events/attachments/optimizing_sds/slides/2300/GlusterOnNVMe_FOSDEM2018.pdf

On the same-class server hardware, following their tuning recommendations, etc. I just run 8 times slower.
So it seems that RH insiders are the only people knows how to setup real GlusterFS installation properly :(.

Dmitry
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