From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:59241 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758147Ab3EYWtU convert rfc822-to-8bit (ORCPT ); Sat, 25 May 2013 18:49:20 -0400 From: Martin Steigerwald To: Leonidas Spyropoulos Cc: Duncan <1i5t5.duncan@cox.net>, "linux-btrfs@vger.kernel.org" Subject: Re: Recommended settings for SSD Date: Sun, 26 May 2013 00:49:18 +0200 Message-ID: <1678992.ZSqdH6UUdd@merkaba> In-Reply-To: References: <1751895.r3q1HmeO0C@merkaba> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am Samstag, 25. Mai 2013, 23:29:41 schrieb Leonidas Spyropoulos: > On Sat, May 25, 2013 at 1:13 PM, Martin Steigerwald wrote: > > Am Samstag, 25. Mai 2013, 03:58:12 schrieb Duncan: > > [...] > > And can be verified by: > > > > martin@merkaba:~> grep ssd /proc/mounts > > /dev/mapper/merkaba-debian / btrfs rw,noatime,compress=lzo,ssd,space_cache 0 0 > > /dev/mapper/merkaba-debian /mnt/debian-zeit btrfs > > rw,noatime,compress=lzo,ssd,space_cache 0 0 > > /dev/mapper/merkaba-home /home btrfs rw,noatime,compress=lzo,ssd,space_cache 0 > > 0 > > /dev/mapper/merkaba-home /mnt/home-zeit btrfs > > rw,noatime,compress=lzo,ssd,space_cache 0 0 > > martin@merkaba:~> grep ssd /etc/fstab > > martin@merkaba:~#1> > > [...] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > I see you are using compression. I don't have compression at the > moment and I would like to use it. What will happen to the data that > are already on the partitions? Will it be compressed when I use them? > Do I have to re-write them? Would it be compressed with btrfs defrag > command? > > Thanks for the information Only new or defragmented data as Harald explained already. Beware: I wouldn´t use compression on SSDs that compress themselves, like any modern SandForce SSDs I bet. The Intel SSD 320 in use here doesn´t compress itself, it just encrypts. -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7