From mboxrd@z Thu Jan 1 00:00:00 1970 From: Calvin Walton Subject: Re: btrfs fi df gives only the total size that is currently allocated Date: Sat, 19 Mar 2011 15:51:49 -0400 Message-ID: <1300564311.19466.10.camel@nayuki.kepstin.ca> References: <4D850120.9030701@torus.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-btrfs@vger.kernel.org To: Gal Buki Return-path: In-Reply-To: <4D850120.9030701@torus.ch> List-ID: On Sat, 2011-03-19 at 21:16 +0200, Gal Buki wrote: > Hi >=20 > I made a test RAID 10 with several old disks with various sizes. > I copied some files (~800MB) > When using btrfs fi df /mountpoint I get > Data: total=3D1.00GB, used=3D800.00MB > When I copy another ~800MB I get a total size of 2GB. >=20 > This goes on and on until I hit the max size of the RAID. > e.g. > Data: total=3D5.00GB, used=3D4.97GB >=20 > Is there a way to see what the max size will be without having to fil= l=20 > the RAID first? As I understand it: the simple answer is, unfortunately, =E2=80=9Cno=E2= =80=9D. Because metadata and data chunks are allocated on demand depending on how you use the space, the best you could do would be to make a guess based on current allocation ratios. That is something which is pretty hard to do manually though=E2=80=94 particularly in the case of differently-sized disks=E2=80=94so some sor= t of estimation tool could be useful. (But it would be just that: an estimate, not an exact count.) This will get worse once btrfs supports having data with different raid levels on the same filesystem, because you=E2=80=99ll have different am= ounts of =E2=80=9Cavailable=E2=80=9D space depending on which raid type the data= in question is stored with. --=20 Calvin Walton -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html