From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Mason Subject: Re: [PATCH] Btrfs-progs: btrfs file system size should be bigger then 256m Date: Mon, 05 Jan 2009 11:39:36 -0500 Message-ID: <1231173576.4290.138.camel@think.oraclecorp.com> References: <49621CBA.2080802@wpkg.org> <49622525.80001@schleiser.de> <49622BFC.7040105@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Kaspar Schleiser , linux-btrfs@vger.kernel.org To: Tomasz Chmielewski Return-path: In-Reply-To: <49622BFC.7040105@wpkg.org> List-ID: On Mon, 2009-01-05 at 16:49 +0100, Tomasz Chmielewski wrote: > Kaspar Schleiser schrieb: > > Hey, > > > > Tomasz Chmielewski wrote: > >>> This has been bothering me for some time. Why does btrfs need to have > >>> a disk greater then 256M? I could see a much smaller limit, say 16M > >>> but why so much? The file system itself does not need that much space > >>> for its own use. > >> > >> In other words, 256M limit rather disqualifies btrfs as a filesystem > >> i.e. for /boot, doesn't it? > > When 1G is just 10c? > > Maybe when talking about traditional HDDs. > Anything flash-based is still $2-$5 per 1G. > > I have some SAN devices booting off 512MB or 1G builtin flash. Having > 256M for /boot there would not leave much more space for the operating > system. > > Why separate /boot? It's still needed for encrypted rootfs or more fancy > partitioning (like / on LVM, at least until GRUB2 is stable and is > shipped by major distros). > > > Seriously, what are the technical reasons that btrfs needs so much space > for a minimal filesystem? This is mostly to help prevent crashes on enospc. As we fixup the kernel code, the 256MB limit will go away. -chris