From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sander Subject: Re: worse than expected compression ratios with -o compress Date: Sun, 17 Jan 2010 15:34:22 +0100 Message-ID: <20100117143422.GA18448@cumulus> References: Reply-To: sander@humilis.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-btrfs@vger.kernel.org To: Jim Faulkner Return-path: In-Reply-To: List-ID: Hello Jim, Jim Faulkner wrote (ao): > To contrast, rzip can compress a database dump of this data to > around 7% of its original size. This is an older database dump, > which is why it is smaller. Before: > -rw------- 1 root root 69G 2010-01-15 14:55 mysqlurdbackup.2010-01-15 > and after: > -rw------- 1 root root 5.2G 2010-01-16 05:34 mysqlurdbackup.2010-01-15.rz > > Of course it took 15 hours to compress the data, and btrfs wouldn't > be able to use rzip for compression anyway. The difference between a life MySQL database and a dump of that database is that the dump is text, while the database files are binary. A fair comparison would be to compress the actual database files. With kind regards, Sander -- Humilis IT Services and Solutions http://www.humilis.net