From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:47506 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751091AbaDUGyz (ORCPT ); Mon, 21 Apr 2014 02:54:55 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Wc87u-00030l-CD for linux-btrfs@vger.kernel.org; Mon, 21 Apr 2014 08:54:50 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 21 Apr 2014 08:54:50 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 21 Apr 2014 08:54:50 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: btrfs fi df "unknown" chunk type Date: Mon, 21 Apr 2014 06:54:38 +0000 (UTC) Message-ID: References: <9C28A5D6-F223-400F-9471-85C0F88FA939@colorremedies.com> <1B7A7ABD-FF67-4ED0-A5E8-F24C0BBA4B0D@colorremedies.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Chris Murphy posted on Sun, 20 Apr 2014 14:26:37 -0600 as excerpted: > On Apr 20, 2014, at 2:18 PM, Chris Murphy wrote: >> What is unknown? > > > /dev/sd[bcd] are 2GB, 3GB, and 4GB respectively. > > [root@localhost ~]# mkfs.btrfs -d raid0 -m raid1 /dev/sd[bcd] [...] > [root@localhost ~]# mount /dev/sdb /mnt > [root@localhost ~]# btrfs fi show > Label: none uuid: ff85abb0-3398-40a0-b06c-8146cb1bfda0 > Total devices 3 FS bytes used 112.00KiB > devid 1 size 2.00GiB used 787.94MiB path /dev/sdb > devid 2 size 3.00GiB used 315.19MiB path /dev/sdc > devid 3 size 4.00GiB used 775.94MiB path /dev/sdd > > [root@localhost ~]# btrfs fi df /mnt > Data, RAID0: total=921.56MiB, used=256.00KiB > Data, single: total=8.00MiB, used=0.00 > System, RAID1: total=8.00MiB, used=16.00KiB > System, single: total=4.00MiB, used=0.00 > Metadata, RAID1: total=460.75MiB, used=112.00KiB > Metadata, single: total=8.00MiB, used=0.00 > unknown, single: total=16.00MiB, used=0.00 I have no clue /what/ that unknown is. If I didn't see the mkfs.btrfs right above, I'd guess it was filesystem damage of some sort, but with the mkfs.btrfs, and with all three devices very specifically trimmed, I haven't the foggiest. Meanwhile... > [root@localhost ~]# btrfs balance start /mnt > Done, had to relocate 6 out of 6 chunks Count. There's 7 items listed above including unknown. Only 6 of 6 chunks relocated. Conclusion given the below, balance didn't touch that unknown at all! > [root@localhost ~]# btrfs fi show > Label: none uuid: ff85abb0-3398-40a0-b06c-8146cb1bfda0 > Total devices 3 FS bytes used 384.00KiB > devid 1 size 2.00GiB used 0.00 path /dev/sdb > devid 2 size 3.00GiB used 288.00MiB path /dev/sdc > devid 3 size 4.00GiB used 1.19GiB path /dev/sdd > > [root@localhost ~]# btrfs fi df /mnt > Data, single: total=928.00MiB, used=256.00KiB > System, RAID1: total=32.00MiB, used=16.00KiB > Metadata, RAID1: total=256.00MiB, used=112.00KiB > unknown, single: total=16.00MiB, used=0.00 > > > An unknown chunk type here too, exists even after a balance. > Along with a weird allocation different merely due to > balancing an empty file system. As I concluded above, unknown untouched by the balance. The different allocation (raid0 to single) with the empty-filesystem balance is I believe a known issue. Meanwhile, based on those numbers, we have * data single 928 MiB, as one chunk on the 4G (largest) device * system and metadata raid1 32 + 256 = 288 MiB on each of the two largest devices (3G and 4G). * 928 + 256 + 32 = 1216 MiB / 1024 = 1.1875 GiB = show reported usage, 4G device * 256 + 32 = 288 MiB, show reported usage, 3G device * show doesn't seem to report the 16 MiB "unknown" on any of the three Out of curiosity... What does a btrfs balance start -v (verbose) report? What about btrfs scrub start -BdR (no-background, per-device, raw stats)? What about btrfs check? (Obviously without the --repair, so it's read-only) Of course both the command output and the related dmesg, if any, for all the above. And... given the existence of that strange unknown even after the mkfs.btrfs trims... Does a badblocks run (with either -n or -w and -v) turn up anything strange? I'd ask about smartctl -A if it wasn't virtual... -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman