If you’re using rotational hard drives, Linux’s default IO scheduler can interact very badly with ZFS’s IO scheduler, greatly reducing performance. This is further exaggerated if you have any SMR devices due to their pathological worst-case performance characteristics. I’ve found that switching to “none” (this was called “noop” historically) can improve performance by a full […]

I’m using [[ZFS]] (via ZFS-FUSE), and at one point a zpool status gave me this rather scary report: zpool status pool: srv state: ONLINE status: One or more devices has experienced an unrecoverable error. An attempt was made to correct the error. Applications are unaffected. action: Determine if the device needs to be replaced, and […]