On Mon, Nov 4, 2013 at 12:15 PM, Markus Falb <wnefal at gmail.com> wrote: > >> 3) NEVER let a zpool fill up above about 70% full, or the performance >> really goes downhill. > > Why is it? It sounds cost intensive, if not ridiculous. > Disk space not to used, forbidden land... > Is the remaining 30% used by some ZFS internals? Probably just simple physics. If ZFS is smart enough to allocate space 'near' other parts of the related files/directories/inodes it will have to do worse when there aren't any good choices and it has to fragment things into the only remaining spaces and make the disk heads seek all over the place. Might not be a big problem on SSD's though. -- Les Mikesell lesmikesell at gmail.com