Thanks for the input, Gregory and Josh. What I am hearing is that this has everything to do with the filesystem, and nothing to do with the block device on Ceph. Thanks again, - Travis On Wed, Oct 10, 2012 at 1:55 PM, Gregory Farnum <greg@xxxxxxxxxxx> wrote: > I don't know the ext4 internals at all, but filesystems tend to > require allocation tables of various sorts (for managing extents, > etc). 7.5GB out of 500GB seems a little large for that metadata, but > isn't ridiculously so... > > On Wed, Oct 10, 2012 at 10:28 AM, Damien Churchill <damoxc@xxxxxxxxx> wrote: >> On 10 October 2012 18:10, Travis Rhoden <trhoden@xxxxxxxxx> wrote: >>> Additionally, 500G - 7.5G != 467G (the number shown as Avail). Why >>> the huge discrepancy? I don't expect the numbers to add up exact due >>> to rounding from kB, MB, GB, etc, but they should be darn close, a la >> >> ext4 keeps some reserved space, 5% by default, for when the disk is >> full so you are still able to use the filesystem and clean it up. >> >> 500G * 0.05 = 25G >> 500G - (25G + 7.5G) = 467G >> >> Can't tell you where the 7.5G comes from though! >> -- >> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
