From: Eric Sandeen Subject: Re: "data=writeback" and TRIM don't get along Date: Wed, 07 Apr 2010 20:22:39 -0500 Message-ID: <4BBD2FDF.4040407@redhat.com> References: <4BBD285B.9000603@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org To: Nebojsa Trpkovic Return-path: Received: from mx1.redhat.com ([209.132.183.28]:14146 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752954Ab0DHBWp (ORCPT ); Wed, 7 Apr 2010 21:22:45 -0400 In-Reply-To: <4BBD285B.9000603@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Nebojsa Trpkovic wrote: > Hello. > > TRIM command issued to SSD doesn't work with this mount options: > > ============================ > rootfs / rootfs rw 0 0 > /dev/root / ext4 > rw,noatime,commit=100,barrier=0,nobh,stripe=128,data=writeback,discard 0 0 > proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 > rc-svcdir /lib64/rc/init.d tmpfs > rw,nosuid,nodev,noexec,relatime,size=1024k,mode=755 0 0 > sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 > udev /dev tmpfs rw,nosuid,relatime,size=10240k,mode=755 0 0 > devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620 0 0 > shm /dev/shm tmpfs rw,nosuid,nodev,noexec,relatime 0 0 > ============================ How does it fail? > Removing "data=writeback" option from /etc/fstab and from rootflags in > kernel boot options results in TRIM working just like it should. > > So, the question is: > > Is this "data=writeback" and TRIM incompatibility a bug or a feature? :) Surely a bug. :) If you can provide details we'll look into it. (perhaps it's obvious on first try but still worth saying exactly what problematic behavior you saw, when reporting a bug you encountered) Thanks, -Eric