From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: Disk space usage displayed incorrectly? Date: Mon, 12 Jul 2010 21:16:50 -0400 Message-ID: <20100713011650.GN563@think> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs@vger.kernel.org To: jck Return-path: In-Reply-To: List-ID: On Sat, Jul 10, 2010 at 07:22:26AM +0530, jck wrote: > Hello, > when i check diskspace usage of a btrfs partition using df i get the > wrong free space, this is expected i think. We do try to take the raid levels into account during df, but only for the space that is already allocated. > However even when i use 'btrfs filesystem df' I get wrong freespace: > Data: total=123.58GB, used=87.31GB > Metadata: total=61.00GB, used=396.29MB > System: total=32.00MB, used=16.00KB > > Does this mean that after the 123 GB of 'Data' fills up I wont be able > to add more stuff to the partition? > I'm using btrfs-progs-git (jul 10) This does reflect the space that is allocated, but the drive itself may have more free space. btrfs filesystem show will give you a few more details. Basically btrfs allocates from the drive in chunks of about 1GB and then puts the file data or metadata into those chunks. So if you do a mkfs and then create one file, you might have 1TB of space on the drive that hasn't been allocated yet. -chris