> On Jun 16, 2015, at 8:14 PM, Chris Murphy <li...@colorremedies.com> wrote: > > On Tue, Jun 16, 2015 at 5:58 PM, Duncan <1i5t5.dun...@cox.net> wrote: > >> On a current kernel unlike older ones, btrfs actually automates entirely >> empty chunk reclaim, so this problem doesn't occur anything close to near >> as often as it used to. However, it's still possible to have mostly but >> not entirely empty chunks that btrfs won't automatically reclaim. A >> balance can be used to rewrite and combine these mostly empty chunks, >> reclaiming the space saved. This is what Hugo was recommending. > > Yes, as little as a -dusage=5 (data chunks that are 5% or less full) > can clear the problem and is very fast, seconds. Possibly a bit > longer, many seconds o single digit minutes is -dusage=15. I haven't > done a full balance in forever.
Yes, on this 80% full 6x4TB RAID10 -dusage=15 took 2 seconds and relocated "0 out of 3026 chunks”. Out of curiosity, I had to use -dusage=90 to have it relocate only 1 chunk and it took les than 30 seconds. So I put a -dusage=25 in the weekly cron just before the scrub. FYI. Thanks for your help.-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
