From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Pottage Subject: Re: snapshot limit? Date: Tue, 17 Aug 2010 22:13:41 +0100 Message-ID: <4C6AFB85.9020207@electric-spoon.com> References: <4C6AC9AC.9000503@noir.com> <4C6AD78B.8070503@noir.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: "linux-btrfs@vger.kernel.org" Return-path: In-Reply-To: <4C6AD78B.8070503@noir.com> List-ID: On 17/08/10 19:40, K. Richard Pixley wrote: > On 8/17/10 11:05 , Dhiru Kholia wrote: >> On Tue, Aug 17, 2010 at 10:41 AM, K. Richard Pixley > > wrote: >> > Is there a limit to the number of snapshots that can exist on a file >> system >> > concurrently? >> >> According to https://help.ubuntu.com/community/btrfs "You can create >> as many subvolumes as you want, as long as you have storage capacity." >> >> -- >> Cheers, >> Dhiru >> > > Yes. But if there's a limit to the number of paths that can point to > a single file, then that's not strictly true. Rather, there's a limit > based on the number of snapshots pointing to the same file. Would that limit also apply to de-duplicated copies of a file ? Suppose I have tree under a btrfs file-system with lots of identical files. (eg zero length lock files), and I run a de-duplication script on it, to turn all those files into one, and then make a series of snapshots. 100 identical files multiplied by 100 snapshots (eg. daily for a few months), comes to a rather large number of links pointing to the same file. -- David Pottage