Re: how to tell if TRIM is working
- Reply: Warner Losh : "Re: how to tell if TRIM is working"
- In reply to: Warner Losh : "Re: how to tell if TRIM is working"
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Thu, 02 May 2024 14:19:51 UTC
On 5/2/2024 10:16 AM, Warner Losh wrote: > > When trims are fast, you want to send them to the drive as soon as you > know the blocks are freed. UFS always does this (if trim is enabled at > all). > ZFS has a lot of knobs to control when / how / if this is done. > > vfs.zfs.vdev.trim_min_active: 1 > vfs.zfs.vdev.trim_max_active: 2 > vfs.zfs.trim.queue_limit: 10 > vfs.zfs.trim.txg_batch: 32 > vfs.zfs.trim.metaslab_skip: 0 > vfs.zfs.trim.extent_bytes_min: 32768 > vfs.zfs.trim.extent_bytes_max: 134217728 > vfs.zfs.l2arc.trim_ahead: 0 > > I've not tried to tune these in the past, but you can see how they affect things. > Thanks Warner, I will try and play around with these values to see if they impact things. BTW, do you know what / why things would be "skipped" during trim events ? kstat.zfs.zrootoffs.misc.iostats.trim_bytes_failed: 0 kstat.zfs.zrootoffs.misc.iostats.trim_extents_failed: 0 kstat.zfs.zrootoffs.misc.iostats.trim_bytes_skipped: 5968330752 kstat.zfs.zrootoffs.misc.iostats.trim_extents_skipped: 503986 kstat.zfs.zrootoffs.misc.iostats.trim_bytes_written: 181593186304 kstat.zfs.zrootoffs.misc.iostats.trim_extents_written: 303115