File:LUG2019-Introducing Pool Quotas-Spitz.pdf

With the deployment of heterogenous clusters consisting of some flash OSTs and some disk OSTs, administrators may need to limit an individual’s consumption of the higher-performance OSTs. The Lustre pools feature allows for the grouping of similar OSTs into performance tiers, and assigning file layouts into these tiers. However, it provides no methods to limit the usage of more desirable / more expensive / smaller capacity tiers. Quota controls are the natural solution to administrative limits on space resource. However, quotas in Lustre today are limited to filesystem-wide quota limits on a per-user, per-group, or per-project basis. We describe a new pool quotas design to extend Lustre’s quotas capabilities to limit allocations within pools. We describe the feature design and explain the initially confusing concepts of using multiple quotas.