From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathijs Kwik Subject: the flushoncommit mount option Date: Wed, 19 May 2010 09:04:35 +0200 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: linux-btrfs@vger.kernel.org Return-path: List-ID: Hi all, Over the past few months, I've been trying out btrfs on separate mountpoints. I like it very much so I would like to try it on my home or root volumes and see if I can do something fun with the snapshots. As btrfs still isn't production-ready, I made sure everything is backed-up to an external ext4 disk. Now when I first moved to try out ext4, there were some issues with the way it handled commits(I think) compared to ext3, which made some desktop-applications act weird. This was fixed later, but I don't remember if it was ext4 to blame or the apps changing their behavior to not depend on ext2/3 semantics. Now, looking at btrfs's mount options, the flushoncommit description sounded vaguely familiar regarding these ext4 oddities. However, I couldn't find a good description of what the (dis)advantages of flushoncommit would be. On the volume I used upto now (music/video storage), I didn't notice any differences, but maybe using it for home (dotfiles) or root will be a bit different. Does anyone remember the ext4 oddities I'm talking about? Are they related to this flushoncommit mount option or am a totally missing the point here? And in case it is related... should I use the option for root or home or is it safe to leave out? Thanks for any information about this. Mathijs FYI: I'm using xubuntu 10.04 64bit, with (backported) 2.6.34 and the latest btrfs-progs from git.