From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leszek Ciesielski Subject: Reporting free space to userspace programs Date: Fri, 30 Oct 2009 12:58:20 +0100 Message-ID: <23a15590910300458y677692bbua62d2b41e9141bc7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: linux-btrfs@vger.kernel.org Return-path: List-ID: Hi, the results of running 'df' against a btrfs volume are somewhat unintuitive from a user point of view. On a single drive btrfs volume, created with 'mkfs.btrfs -m raid1 -d raid1 /dev/sda6', I am getting the following result: /dev/sda6 1.4T 594G 804G 43% /mnt while 'btrfs-show' displays much more expected result: Label: none uuid: 46e2f2b6-e3a6-4b02-8fdc-f9d0fb0882e0 Total devices 1 FS bytes used 593.15GB devid 1 size 1.36TB used 1.26TB path /dev/sda6 IMHO it would be more intuitive for df in this case to show 699GB total capacity (based on the fact that data is mirrored, and users probably are not concerned with metadata handling during normal usage), the 'used space' probably should include the space taken up by metadata in addition to data usage (after all, this space is not available for user data) and free space should report only data space available (because this is what the user is usually expecting). Or, in other words: the result of 'df' should not concern the user with the details of raid0/raid1/raid10 used either for data or metadata. Anyone care to comment? kudos :-) Leszek 'skolima' Ciesielski --- I am running kernel 2.6.31-gentoo and using btrfs-progs 0.19, please excuse me if my comments are no longer relevant (however, I did check commit messages from the version I use up until linux/kernel/git/mason/btrfs-unstable.git master-HEAD and did not find anything related to the topic).