From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from resqmta-po-09v.sys.comcast.net ([96.114.154.168]:50842 "EHLO resqmta-po-09v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935750AbcJRTHD (ORCPT ); Tue, 18 Oct 2016 15:07:03 -0400 Received: from calvin.localdomain ([10.0.0.8]) by beta.localdomain with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1bwZj1-0002HD-SW for linux-btrfs@vger.kernel.org; Tue, 18 Oct 2016 14:06:59 -0500 Received: from tew by calvin.localdomain with local (Exim 4.84_2) (envelope-from ) id 1bwZj1-0006Sl-Nw for linux-btrfs@vger.kernel.org; Tue, 18 Oct 2016 14:06:59 -0500 Date: Tue, 18 Oct 2016 14:06:59 -0500 From: Tim Walberg To: linux-btrfs@vger.kernel.org Subject: Re: question re: trim in btrfs Message-ID: <20161018190659.GC5559@comcast.net> Reply-To: Tim Walberg References: <20161018174238.GB5559@comcast.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20161018174238.GB5559@comcast.net> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Forgot to mention - this was on a rather crusty 4.2.6 kernel. Just upgraded to 4.8.1 and the issue appears to have been resolved... On 10/18/2016 12:42 -0500, Walberg, Tim wrote: >> Unless I'm misinterpreting something it appears that maybe btrfs doesn't pass >> fstrim commands down to the underlying drives when being used in a RAID-1 config. >> >> I have this output from a small script I wrote to run at boot time (and also via >> cron.weekly), rather than using continous trim in the boot options: >> >> # cat /var/log/trim.log >> Thu Oct 13 07:40:07 CDT 2016 >> /boot: 454 MiB (476062720 bytes) trimmed >> >> Thu Oct 13 07:40:08 CDT 2016 >> /: 8.9 GiB (9585152000 bytes) trimmed >> >> Thu Oct 13 07:40:22 CDT 2016 >> /btrfs/0: 0 B (0 bytes) trimmed >> >> /boot and / are mdraid RAID 1 on partitions 1 and 3 of two Samsung 850 Pro SSDs. >> /btrfs/0 is a btrfs-raid RAID 1 of partition 4 on the same two drives. The btrfs >> case does not seem to accomplish anything. By comparison, I have the same drive >> in my laptop, but just a single one, and the non-btrfs-raid-1 file system on one >> of its partitions does run fstrim successfully. >> >> This is quite possibly a known limitation, but I didn't find anything about it >> through some quick searching. Maybe I didn't dive deep enough... >> >> -- >> twalberg@gmail.com, twalberg@comcast.net >> -- >> 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 End of included message -- twalberg@gmail.com, twalberg@comcast.net