[LU-16623] lod_statfs_and_check() does not skip unusable OSTs

Related — Tue, 23 Jan 2024 07:00:34 +0000

The LOV_USES_DEFAULT_STRIPE flag is never set during OST object allocation, so min_stripe_count() does not allow reducing the stripe count set on a file. This can result in the MDS trying to allocate objects on too many OSTs, especially when the space is imbalanced, or OSTs are deactivated by "osp.*.max_create_count=0".

It also appears that lod_statfs_and_check() is expecting lod_statfs_check() to only return -ENOSPC, so it isn't skipping an OST when it is mounted read-only or when max_create_count=0. It would probably be better to change lod_statfs_and_check() to skip the OST if lod_statfs_check() returns any error, since all of them are reasons to skip an OST.

Also, it appears that the merged MDT and OST QOS allocation does skip MDTs marked with OS_STATFS_ENOINO.

Whamcloud Community JIRA

[LU-16623] lod_statfs_and_check() does not skip unusable OSTs