From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f193.google.com ([209.85.213.193]:33592 "EHLO mail-ig0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759071AbcCDWhl (ORCPT ); Fri, 4 Mar 2016 17:37:41 -0500 Received: by mail-ig0-f193.google.com with SMTP id hb3so615649igb.0 for ; Fri, 04 Mar 2016 14:37:40 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 4 Mar 2016 15:37:40 -0700 Message-ID: Subject: Re: ENOSPC while creating snapshot From: Chris Murphy To: nexus@smoula.net Cc: Btrfs BTRFS Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Fri, Mar 4, 2016 at 2:10 PM, wrote: > Hello, > > I'm encountering weird enospc problem while writing to filesystem and > creating snapshot at a same time: > > Steps to reproduce: > > start writing data to filesystem: > > # LC_ALL=C dd if=/dev/zero of=/foobar > dd: writing to '/foobar': No space left on device > 3003803+0 records in > 3003802+0 records out > 1537946624 bytes (1.5 GB, 1.4 GiB) copied, 10.8072 s, 142 MB/s > > in other terminal create read-only (or r/w - results are the same) > # btrfs sub snap -r / /.snap1 > Create a readonly snapshot of '/' in '//.snap1' > > while creating this snapshot, ENOSPC is produced. Known issue. There's a thread already about it somewhere around here in the last 4-6 weeks. (rw,noatime,nodatasum,nodatacow,ssd,discard,space_cache,enospc_debug,commit=900,subvolid=5,subvol=/) Most likely unrelated but commit time of 15 minutes? Umm, OK why? -- Chris Murphy