[lustre-devel] lfs usage with OST pool quota flags

[Spitz, Cory James]

Hello, Gian-Carlo DeFazio.

Sergey Chermencev is the developer who implemented OST Pool Quotas.  I’ve copied him so that he may answer your questions in more detail.  For now, I can say that you can use the following as resources:

https://opensfs.org/wp-content/uploads/2019/07/LUG2019-Introducing_Pool_Quotas-Spitz.pdf
https://vimeo.com/showcase/6042401/video/342817244

And yes, you can use the --pool option in conjunction with the default value flags.  See slide 11 from the referenced pdf as an example.

> Is that already happening? I see that there’s LUDOC-467 to add OST pool quotas to the manual
Yes, https://review.whamcloud.com/#/c/38414 is for it, but it hasn’t landed yet.

-Cory


On 8/31/20, 1:29 PM, "lustre-devel on behalf of Defazio, Gian-Carlo" <lustre-devel-bounces at lists.lustre.org<mailto:lustre-devel-bounces at lists.lustre.org> on behalf of defazio1 at llnl.gov<mailto:defazio1 at llnl.gov>> wrote:

I’m planning to add a feature to lfs-quota (a relatively quick check for EDQUOT)
and I have some questions about how the new OST pool quota feature will change things
with regards to how the quota system works internally and how the lfs-quota options will change.

For how the system actually works internally:
The struct lquota_entry (lqe) now has 2 edquot flags,  lqe_edquot and lge_edquot.
Does lqe_edquot still represent the QMT’s current knowledge about whether or not
an entity has exceeded a quota for the pool associated with the lqe, or do the
lge_edquot flags need to be checked as well to make this determination?

For how lfs-quota works:
There is now a –pool option. Can this flag be used in conjunction with the default value flags
(-U|-G|-P)? Such as
lfs quota -U –pool qpool1 /mnt/lustre
To check the default user quota values for OST pool qpool1?

I’ll need to update lfs-quota.1, lfs-setquota.1, and the lfs.c help section for my feature, but since
the flag I add will have to interact with the –pool flag in some cases, I also need to update those files
for the OST pool quotas. Is that already happening? I see that there’s LUDOC-467 to add OST pool quotas to the manual.

Thanks,
Gian-Carlo DeFazio
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