From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail2.jellyfishnet.co.uk ([93.91.20.10]:34023 "EHLO mail2.jellyfishnet.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754951Ab3HWJOF convert rfc822-to-8bit (ORCPT ); Fri, 23 Aug 2013 05:14:05 -0400 From: Mark Ridley To: "linux-btrfs@vger.kernel.org" Date: Fri, 23 Aug 2013 10:14:02 +0100 Subject: Re: Samba strict allocate = yes stops btrfs compression working Message-ID: In-Reply-To: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: That would be fine, but nodatacow (according to the btrfs wiki) stops compression, so I might as well get the speed benefits of 'strict allocate = yes' which also disables compression. If you want to use BTRFS to store backups then compression has be turned on. Database files like MSSQL usually compress down by 7-10 times, so its a shame to not get this benefit. On 23/08/2013 10:08, "Duncan" <1i5t5.duncan@cox.net> wrote: >Mark Ridley posted on Fri, 23 Aug 2013 09:20:04 +0100 as excerpted: > >> I don't want to try nodatacow (which would probably fix the issue), but >> you lose compression on the whole filesystem, autodefrag doesn't fix it >> either. > >I don't do servantware (in the context of my sig) and thus don't do samba >here, so I'll just black-box that side of things entirely. > >But from the btrfs side, are you considering nodatacow at the filesystem >or individual file level? It seems doing it at the individual file level >might be what you need. > >Note that nodatacow must be set on the file at creation in ordered to >work, which is impractical to do directly. However, if you can arrange >for the files in question to appear in a particular directory, you can >set the nodatacow attribute on the directory, and files created within it >will inherit that. > >It seems to me that should do what you need, PROVIDED that you can >arrange for the files to appear in a particular dir/dir-tree, not more or >less randomly written throughout the entire (btrfs) filesystem. > >-- >Duncan - List replies preferred. No HTML msgs. >"Every nonfree program has a lord, a master -- >and if you use the program, he is your master." Richard Stallman > >-- >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