From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Roberts Subject: Re: [PATCH] Btrfs: dynamically remove unused block groups Date: Tue, 30 Nov 2010 21:53:41 -0700 Message-ID: <970f54e0098c313a4b780b2356734592@arbitraryconstant.com> References: <1291135590-26775-1-git-send-email-josef@redhat.com> <20101130190100.GA2577@localhost.localdomain> <20101130193512.GB2577@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Cc: To: Josef Bacik Return-path: In-Reply-To: <20101130193512.GB2577@localhost.localdomain> List-ID: Hello, What happens in the event the filesystem has mostly been cleared out, but there's a few things left? For example, several of the chunks might be at very low usage, but not zero. Would the user be able to defragment the filesystem to cause these chunks to be consolidated? Regards, -Anthony > Yeah 2 things to keep in mind, 1 if you have snapshots you are likely > to not see > data free'd up the way you expect it. The other thing is that > because > everything is COW we can't allocate the newly free'd space until the > transaction > commits, so you may have to wait ~30 seconds or run sync to force the > transaction to commit before you see your space actually free'd up. > Thanks, > > Josef > -- > 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