From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.fusionio.com ([66.114.96.31]:58670 "EHLO mx2.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755826Ab2JRN2y (ORCPT ); Thu, 18 Oct 2012 09:28:54 -0400 Date: Thu, 18 Oct 2012 09:28:50 -0400 From: Chris Mason To: Marguerite Su CC: "linux-btrfs@vger.kernel.org" Subject: Re: initramfs take a long time to load[135s] Message-ID: <20121018132850.GA22010@shiny> References: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Thu, Oct 18, 2012 at 05:29:50AM -0600, Marguerite Su wrote: > Hi, all, > > I ran into a situation that no useful information can be found over > the internet... > > I'm using 3.6.2 + btrfs git compiled using dkms, and I have a 300GB > btrfs /home and 50GB btrfs /: Usually when btrfs is slow to mount, or slow right after a mount it is because we're regenerating the free space cache. This is slow enough that you should be able to see the free space cache threads active even after the initial boot is done. The good news is that you should be able to just let them finish generating the cache and then the problem should go away. If it isn't the free space cache, it'll be a fragmentation problem. The easiest way to tell the difference is to get a few sysrq-w snapshots during the boot. -chris