OST Pool Quotas

Description

OST Pool Quotas feature gives an ability to limit user's(group's/project's) disk usage at OST pool.

Each Quota Pool(QP) duplicates content of OST pool. Thus QP could be tuned with standard lctl pool_new/add/remove/erase commands. All QPs are subset of a global pool that includes all OSTs and MDTs(DOM case).

DOM and MDT pools

From Quota Master point of view "data" MDTs are regular members together with OSTs. But until we haven't a mechanism to group MDTs in pools, Quota Pools support only OSTs.

New options at lfs quota/setquota

2 new options were introduced to support QP at lfs quota and setquota:

• -o "pool_name" is new option to be used with lfs setquota to set quota for user/qroup/project per quota pool.

  Example: lfs setquota -u quota_usr -o "qpool1" -B10M /mnt/lustre

• --pool "pool_name" is an option to show quota for user/group/project per quota pool.

  Example: lfs quota -u quota_usr --pool "qpool1" /mnt/lustre

How To setup QP

Let's imagine you haven't any OST pool(if you want to setup already existed pool, go to 3):

1. lctl pool_new qpool1 /mnt/lustre
2. lctl pool_add qpool1 OST000 /mnt/lustre
3. lfs setquota -u quota_usr -B100T /mnt/lustre /* it is a limit for global pool. QPs don't work properly without that */
4. lfs setquota -u quota_usr -o "qpool1" -B100M /mnt/lustre

Note, you need to setup wide-system hard limit before setting QP limit. If you don't need to limit user at all OSTs and MDTs at system, only per pool, I would recommend to set some unrealistic big hard limit. Without that OSTs don't know that quota for quota_usr is enabled.

Links

Docs

OST Pool Quotas HLD

Tickets

LU-11023

Patches

Name	Landed
LU-11023 quota: remove quota pool ID	yes
LU-11023 quota: quota pools for OSTs	no