Re: Understanding BTRFS storage

On 2015-08-26 22:58, Duncan wrote: Austin S Hemmelgarn posted on Wed, 26 Aug 2015 08:03:40 -0400 as excerpted: On 2015-08-26 07:50, Roman Mamedov wrote: On Wed, 26 Aug 2015 10:56:03 +0200 George Duffield forumscollect...@gmail.com wrote: I'm looking to switch from a 5x3TB mdadm raid5 array

Re: [PATCH] generic/224: Increase filesystem instance size to 1.5 GiB

On 2015-08-31 14:11, Theodore Ts'o wrote: On Sun, Aug 30, 2015 at 08:16:21PM +0530, Chandan Rajendra wrote: For small filesystem instances (i.e. size <= 1 GiB), mkfs.btrfs fails when "data block size" does not match with the "metadata block size" specified on the mkfs.btrfs command line. This

Re: [PATCH v1 0/8] VFS: In-kernel copy system call

On 2015-09-09 14:52, Anna Schumaker wrote: On 09/08/2015 06:39 PM, Darrick J. Wong wrote: On Tue, Sep 08, 2015 at 02:45:39PM -0700, Andy Lutomirski wrote: On Tue, Sep 8, 2015 at 2:29 PM, Darrick J. Wong wrote: On Tue, Sep 08, 2015 at 09:03:09PM +0100, Pádraig Brady

Re: mkfs.btrfs cannot find rotational file for SSD detection for a pmem device

On 2015-09-08 16:00, Elliott, Robert (Persistent Memory) wrote: -Original Message- From: Austin S Hemmelgarn [mailto:ahferro...@gmail.com] Sent: Tuesday, September 8, 2015 7:56 AM Subject: Re: mkfs.btrfs cannot find rotational file for SSD detection for a pmem device On 2015-09-06 13

Re: [PATCH v1 9/8] copy_file_range.2: New page documenting copy_file_range()

On 2015-09-08 16:39, Darrick J. Wong wrote: On Tue, Sep 08, 2015 at 11:04:03AM -0400, Anna Schumaker wrote: On 09/04/2015 05:38 PM, Darrick J. Wong wrote: On Fri, Sep 04, 2015 at 04:17:03PM -0400, Anna Schumaker wrote: copy_file_range() is a new system call for copying ranges of data

Re: Cancel device remove?

On 2015-09-10 09:18, Piotr Pawłow wrote: Hello, Is there some way to cancel a device remove operation? I have discovered that if I reboot that will cancel it, but that's not always possible. What I'm after is something the same as cancelling scrub. I keep running into situations where I want to

Re: Btrfs progs release 4.1

On 2015-09-09 09:25, David Sterba wrote: On Wed, Sep 09, 2015 at 11:24:17AM +0800, Qu Wenruo wrote: The problem is that, for converted image, it's quite possible that data and metadata extent are stored in one chunk even the chunk is not mixed. I'll add fsck support for it soon. That would

Re: mkfs.btrfs cannot find rotational file for SSD detection for a pmem device

On 2015-09-09 08:12, Boaz Harrosh wrote: On 09/09/2015 02:28 PM, Austin S Hemmelgarn wrote: On 2015-09-08 16:00, Elliott, Robert (Persistent Memory) wrote: <> this may actually make things slower (the particular effect of SSD mode is that it tries to spread allocations out a

Re: [PATCH v1 0/8] VFS: In-kernel copy system call

On 2015-09-10 11:10, Anna Schumaker wrote: On 09/09/2015 05:16 PM, Darrick J. Wong wrote: On Wed, Sep 09, 2015 at 02:52:08PM -0400, Anna Schumaker wrote: On 09/08/2015 06:39 PM, Darrick J. Wong wrote: On Tue, Sep 08, 2015 at 02:45:39PM -0700, Andy Lutomirski wrote: On Tue, Sep 8, 2015 at

Re: [PATCH v3 0/9] Btrfs: free space B-tree

ble performance improvements in both general usage and mount times. I also threw everything I can think of at it (short of attempting to craft filesystem images specifically to break it), and nothing broke, so: Tested-by: Austin S. Hemmelgarn <ahferro...@gmail.com> smime.p

Re: BTRFS as image store for KVM?

On 2015-09-16 07:35, Brendan Heading wrote: Btrfs has two possible solutions to work around the problem. The first one is the autodefrag mount option, which detects file fragmentation during the write and queues up the affected file for a defragmenting rewrite by a lower priority worker thread.

Re: FYIO: A rant about btrfs

On 2015-09-16 10:43, M G Berberich wrote: Hello, just for information. I stumbled about a rant about btrfs-performance: http://blog.pgaddict.com/posts/friends-dont-let-friends-use-btrfs-for-oltp MfG bmg It is worth noting a few things that were done incorrectly in this

Re: btrfs kernel warning

certain if disabling qgroups on a volume removes the qgroup metadata, and if the metadata is still there, it might still cause issues. It's worth trying though because it shouldn't make anything worse than it already is. On Tue, Sep 15, 2015 at 12:32 PM, Austin S Hemmelgarn <ahferro...@gmail.

Re: btrfs kernel warning

addresses from the original mail (and then optionally complain to the developers of your e-mail client that it doesn't support functionality that's been standard since before the year 2000). On Tue, Sep 15, 2015 at 12:46 PM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: On 2015-09-15 14:42,

Re: btrfs kernel warning

On 2015-09-15 14:13, Tyler Williams wrote: I've received several kernel warnings over the last few weeks. I checked on the #BTRFS irc channel and it was suggested that I post the relevant information here to see if this was something that I should be worried about. [root@tawilliams ~]# uname

Re: [PATCH v2 8/9] vfs: copy_file_range() can do a pagecache copy with splice

On 2015-09-15 12:38, Darrick J. Wong wrote: On Tue, Sep 15, 2015 at 11:58:04AM -0400, Anna Schumaker wrote: On 09/14/2015 11:32 PM, Darrick J. Wong wrote: On Fri, Sep 11, 2015 at 04:30:21PM -0400, Anna Schumaker wrote: The NFS server will need some kind offallback for filesystems that don't

Re: FYIO: A rant about btrfs

On 2015-09-16 12:45, Martin Tippmann wrote: Hi, 2015-09-16 17:20 GMT+02:00 Austin S Hemmelgarn <ahferro...@gmail.com>: [...] 3. He's testing it for a workload is a known and documented problem for BTRFS, and claiming that that means that it isn't worth considering as a general usage file

Re: FYIO: A rant about btrfs

On 2015-09-16 12:51, Vincent Olivier wrote: Hi, On Sep 16, 2015, at 11:20 AM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: On 2015-09-16 10:43, M G Berberich wrote: Hello, just for information. I stumbled about a rant about btrfs-performance: http://blog.pgaddict.com/posts/f

Re: FYIO: A rant about btrfs

On 2015-09-16 12:25, Zia Nayamuth wrote: Some response to your criticism: 1. How would that hole fare with a fully battery-backed/flash-backed path (battery-backed or flash-backed HBA with disks with full power-loss protection, like the Intel S3500)? In such a situation (quite commonplace in

Re: FYIO: A rant about btrfs

On 2015-09-16 15:04, Vincent Olivier wrote: On Sep 16, 2015, at 2:22 PM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: On 2015-09-16 12:51, Vincent Olivier wrote: Hi, On Sep 16, 2015, at 11:20 AM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: On 2015-09-16 10:43, M

Re: FYIO: A rant about btrfs

On 2015-09-16 19:31, Hugo Mills wrote: On Wed, Sep 16, 2015 at 03:21:26PM -0400, Austin S Hemmelgarn wrote: On 2015-09-16 12:45, Martin Tippmann wrote: 2015-09-16 17:20 GMT+02:00 Austin S Hemmelgarn <ahferro...@gmail.com>: [...] [...] From reading the list I understand that btrfs is

Re: [PATCH v2 10/9] copy_file_range.2: New page documenting copy_file_range()

On 2015-09-13 03:50, Michael Kerrisk (man-pages) wrote: Hi Anna, On 09/11/2015 10:30 PM, Anna Schumaker wrote: copy_file_range() is a new system call for copying ranges of data completely in the kernel. This gives filesystems an opportunity to implement some kind of "copy acceleration", such

Re: Add stripes filter

On 2015-09-29 08:00, David Sterba wrote: On Mon, Sep 28, 2015 at 05:57:05PM +, Gabríel Arthúr Pétursson wrote: The attached patches to linux and btrfs-progs add support for filtering based on the number of strips in a block when balancing. What usecase do you want to address? As I

Re: BTRFS as image store for KVM?

On 2015-10-02 00:21, Russell Coker wrote: On Sat, 26 Sep 2015 12:20:41 AM Austin S Hemmelgarn wrote: FYI: Linux pagecache use LRU cache algo, and in general case it's working good enough I'd argue that 'general usage' should be better defined in this statement. Obviously, ZFS's ARC

Re: [PATCH] btrfs: Fix no space bug caused by removing bg

On 2015-09-23 09:28, David Sterba wrote: On Tue, Sep 22, 2015 at 03:39:30PM +, Hugo Mills wrote: The way I would expect things to work is that a new subvolume inherits it's properties from it's parent (if it's a snapshot), Definitely this. or from the next higher subvolume it's

Re: Btrfs check dont repair

On 2015-09-23 10:39, Vackář František wrote: Hello, i have problem with my btrfs, can you help me, please? Its on my notebook. Sometimes it exhausted battery during sleep and died. But everytime FS was ok. But ones mount fail. Do you have any idea how repair it? First off, the fact that you

Re: RAID1 storage server won't boot with one disk missing

On 2015-09-22 14:35, Chris Murphy wrote: On Tue, Sep 22, 2015 at 7:21 AM, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: It's not a bad idea, except that it changes established usage, and there are probably some people out there who depend on the current behavior. If we do go th

Re: [PATCH] btrfs: Fix no space bug caused by removing bg

On 2015-09-22 13:32, Austin S Hemmelgarn wrote: On 2015-09-22 11:39, Hugo Mills wrote: On Tue, Sep 22, 2015 at 10:54:45AM -0400, Austin S Hemmelgarn wrote: On 2015-09-22 10:36, Hugo Mills wrote: On Tue, Sep 22, 2015 at 04:23:33PM +0200, David Sterba wrote: On Tue, Sep 22, 2015 at 01:41:31PM

Re: [PATCH] btrfs: Fix no space bug caused by removing bg

On 2015-09-22 11:39, Hugo Mills wrote: On Tue, Sep 22, 2015 at 10:54:45AM -0400, Austin S Hemmelgarn wrote: On 2015-09-22 10:36, Hugo Mills wrote: On Tue, Sep 22, 2015 at 04:23:33PM +0200, David Sterba wrote: On Tue, Sep 22, 2015 at 01:41:31PM +, Hugo Mills wrote: On Tue, Sep 22, 2015

Re: btrfs: obtain block checksums from user space

On 2015-09-24 14:48, Matwey V. Kornilov wrote: 2015-09-24 21:35 GMT+03:00 Austin S Hemmelgarn <ahferro...@gmail.com>: On 2015-09-24 14:06, Matwey V. Kornilov wrote: Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I cou

Re: btrfs: obtain block checksums from user space

On 2015-09-24 14:06, Matwey V. Kornilov wrote: Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I could use the checksums in the manner like rsync does, but safe both CPU (because csums are already calculated for the file) and

Re: RAID1 storage server won't boot with one disk missing

On 2015-09-21 16:35, Erkki Seppala wrote: Gareth Pye writes: People tend to be looking at BTRFS for a guarantee that data doesn't die when hardware does. Defaults that defeat that shouldn't be used. However, data is no more in danger at startup than it is at the

Re: [PATCH] btrfs: Fix no space bug caused by removing bg

On 2015-09-22 10:36, Hugo Mills wrote: On Tue, Sep 22, 2015 at 04:23:33PM +0200, David Sterba wrote: On Tue, Sep 22, 2015 at 01:41:31PM +, Hugo Mills wrote: On Tue, Sep 22, 2015 at 03:36:43PM +0200, Holger Hoffstätte wrote: On 09/22/15 14:59, Jeff Mahoney wrote: (snip) So if they way we

Re: RAID1 storage server won't boot with one disk missing

On 2015-09-22 08:51, Qu Wenruo wrote: 在 2015年09月22日 19:32, Austin S Hemmelgarn 写道: On 2015-09-21 16:35, Erkki Seppala wrote: Gareth Pye <gar...@cerberos.id.au> writes: People tend to be looking at BTRFS for a guarantee that data doesn't die when hardware does. Defaults that

Re: FYIO: A rant about btrfs

On 2015-09-17 11:57, Martin Steigerwald wrote: Am Mittwoch, 16. September 2015, 23:29:30 CEST schrieb Hugo Mills: but even then having write-barriers turned off is still not as safe as having them turned on. Most of the time when I've tried testing with 'nobarrier' (not just on BTRFS but on

Re: FYIO: A rant about btrfs

On 2015-09-17 20:34, Duncan wrote: Zygo Blaxell posted on Wed, 16 Sep 2015 18:08:56 -0400 as excerpted: On Wed, Sep 16, 2015 at 03:04:38PM -0400, Vincent Olivier wrote: OK fine. Let it be clearer then (on the Btrfs wiki): nobarrier is an absolute no go. Case closed. Sometimes it is useful

Re: FYIO: A rant about btrfs

On 2015-09-17 10:52, Aneurin Price wrote: On 16 September 2015 at 20:21, Austin S Hemmelgarn <ahferro...@gmail.com> wrote: ZFS has been around for much longer, it's been mature and feature complete for more than a decade, and has had a long time to improve performance wise. It is imp

Re: RAID1 storage server won't boot with one disk missing

On 2015-09-17 16:18, Chris Murphy wrote: On Thu, Sep 17, 2015 at 1:02 PM, Roman Mamedov wrote: On Thu, 17 Sep 2015 19:00:08 +0200 Goffredo Baroncelli wrote: On 2015-09-17 17:18, Anand Jain wrote: it looks like -o degraded is going to be a very

Re: BTRFS as image store for KVM?

On 2015-09-17 14:35, Chris Murphy wrote: On Thu, Sep 17, 2015 at 11:56 AM, Gert Menke wrote: Hi, thank you for your answers! So it seems there are several suboptimal alternatives here... MD+LVM is very close to what I want, but md has no way to cope with silent data

Re: BTRFS as image store for KVM?

On 2015-09-25 08:48, Rich Freeman wrote: On Sat, Sep 19, 2015 at 9:26 PM, Jim Salter wrote: ZFS, by contrast, works like absolute gangbusters for KVM image storage. I'd be interested in what allows ZFS to handle KVM image storage well, and whether this could be implemented

Re: BTRFS as image store for KVM?

ood caching algorithm?). On 09/25/2015 09:04 AM, Austin S Hemmelgarn wrote: you really need to give specifics on how you have ZFS set up in that case. smime.p7s Description: S/MIME Cryptographic Signature

Re: BTRFS as image store for KVM?

pect ext4 on mdraid5 to perform. ZFS might or might not do a better job of managing fragmentation; I really don't know. I strongly suspect the design difference between the kernel's simple FIFO page cache and ZFS' weighted cache makes a really, really big difference. On 09/25/2015 09:04 AM,

Re: BTRFS as image store for KVM?

On 2015-10-05 07:16, Lionel Bouton wrote: Hi, Le 04/10/2015 14:03, Lionel Bouton a écrit : [...] This focus on single reader RAID1 performance surprises me. 1/ AFAIK the kernel md RAID1 code behaves the same (last time I checked you need 2 processes to read from 2 devices at once) and I've

Issues with unmountable BTRFS raid1 filesystem

I've been having issues recently with a relatively simple setup using a two device BTRFS raid1 on top of two two device md RAID0's, and every time I've rebooted since starting trying to use this particular filesystem, I've found it unable to mount and had to recreate it from scratch. This is

Re: BTRFS as image store for KVM?

On 2015-10-05 10:04, Duncan wrote: On Mon, 5 Oct 2015 13:16:03 +0200 Lionel Bouton wrote: To better illustrate my point. According to Phoronix tests, BTRFS RAID-1 is even faster than md RAID1 most of the time.

Re: Scrub on btrfs single device only to detect errors, not correct them?

On 2015-12-07 09:47, Jon Panozzo wrote: And I'll throw this question out to everyone: Let's say I have a means of providing parity for a btrfs device, but in a way that's external to btrfs (imagine a btrfs single device as part of a hardware or software RAID). If BTRFS detected an error during

Re: Scrub on btrfs single device only to detect errors, not correct them?

On 2015-12-07 10:12, Jon Panozzo wrote: This is what I was thinking as well. In my particular use-case, parity is only really used today to reconstruct an entire device due to a device failure. I think if btrfs scrub detected errors on a single device, I could do a "reverse reconstruct" where

Re: [PATCH] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-08 01:08, Qu Wenruo wrote: Austin S Hemmelgarn wrote on 2015/12/07 11:36 -0500: On 2015-12-07 01:06, Qu Wenruo wrote: Introduce a new mount option "nologreplay" to co-operate with "ro" mount option to get real readonly mount, like "norecovery" i

Re: [PATCH] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-07 18:06, Eric Sandeen wrote: On 12/7/15 2:54 PM, Christoph Anton Mitterer wrote: ... 2) a section that describes "ro" in btrfs-mount(5) which describes that normal "ro" alone may cause changes on the device and which then refers to hard-ro and/or the list of options (currently

Re: Scrub: no spae left on device

On 2015-12-08 10:06, Marc MERLIN wrote: Howdy, Why would scrub need space and why would it cancel if there isn't enough of it? (kernel 4.3) Wild guess here, but maybe scrub unconditionally updates the error counters, regardless of whether any errors were found or not? smime.p7s

Re: [PATCH v2] btrfs: Introduce new mount option to disable tree log replay

ran against the last version, still no issues, so: Tested-by: Austin S. Hemmelgarn smime.p7s Description: S/MIME Cryptographic Signature

Re: [PATCH] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-08 14:20, Christoph Anton Mitterer wrote: On Tue, 2015-12-08 at 07:15 -0500, Austin S Hemmelgarn wrote: Despite this, it really isn't a widely known or well documented behavior outside of developers, forensic specialists, and people who have had to deal with the implications it has

Re: compression disk space saving - what are your results?

On 2015-12-02 08:53, Tomasz Chmielewski wrote: On 2015-12-02 22:03, Austin S Hemmelgarn wrote: From these numbers (124 GB used where data size is 153 GB), it appears that we save around 20% with zlib compression enabled. Is 20% reasonable saving for zlib? Typically text compresses much better

Re: compression disk space saving - what are your results?

On 2015-12-02 09:03, Imran Geriskovan wrote: What are your disk space savings when using btrfs with compression? * There's the compress vs. compress-force option and discussion. A number of posters have reported that for mostly text, compress didn't give them expected compression results and

Re: utils version and convert crash

On 2015-12-02 08:45, Duncan wrote: Austin S Hemmelgarn posted on Wed, 02 Dec 2015 07:25:13 -0500 as excerpted: On 2015-12-02 05:01, Duncan wrote: [on unverified errors returned by scrub] Unverified errors are, I believe[1], errors where a metadata block holding checksums itself has

Re: Bug/regression: Read-only mount not read-only

On 2015-12-02 11:54, Eric Sandeen wrote: On 12/2/15 3:23 AM, Qu Wenruo wrote: Qu Wenruo wrote on 2015/12/02 17:06 +0800: Russell Coker wrote on 2015/12/02 17:25 +1100: On Wed, 2 Dec 2015 06:05:09 AM Eric Sandeen wrote: yes, xfs does; we have "-o norecovery" if you don't want that, or

Re: Bug/regression: Read-only mount not read-only

On 2015-12-02 18:40, Qu Wenruo wrote: On 12/03/2015 06:48 AM, Eric Sandeen wrote: On 12/2/15 11:48 AM, Austin S Hemmelgarn wrote: On a side note, do either XFS or ext4 support removing the norecovery option from the mount flags through mount -o remount? Even if they don't, that might

Re: compression disk space saving - what are your results?

On 2015-12-03 01:29, Duncan wrote: Austin S Hemmelgarn posted on Wed, 02 Dec 2015 09:39:08 -0500 as excerpted: On 2015-12-02 09:03, Imran Geriskovan wrote: What are your disk space savings when using btrfs with compression? [Some] posters have reported that for mostly text, compress didn't

Re: 3.16.0 Debian kernel hang

On 2015-12-04 05:00, Russell Coker wrote: One of my test laptops started hanging on mounting the root filesystem. I think that it had experience an unexpected power outage prior to that which may have caused corruption. When I tried to mount the root filesystem the mount process would stick in

Re: compression disk space saving - what are your results?

On 2015-12-03 07:09, Imran Geriskovan wrote: On a side note, I really wish BTRFS would just add LZ4 support. It's a lot more deterministic WRT decompression time than LZO, gets a similar compression ratio, and runs faster on most processors for both compression and decompression. Relative

Re: Bug/regression: Read-only mount not read-only

On 2015-12-02 18:51, Hugo Mills wrote: On Thu, Dec 03, 2015 at 07:40:08AM +0800, Qu Wenruo wrote: On 12/03/2015 06:48 AM, Eric Sandeen wrote: On 12/2/15 11:48 AM, Austin S Hemmelgarn wrote: On a side note, do either XFS or ext4 support removing the norecovery option from the mount flags

Re: Very various speed of grep operation on btrfs partition

On 2015-12-03 14:36, Михаил Гаврилов wrote: Today on work I needed searching some strings in repository. Only machine with windows was available. I am was using grep from Cygwin for this task and I am was surprised about speed of NTFS partition.I decided to repeat this task on my home Linux

Re: 3.16.0 Debian kernel hang

On 2015-12-04 08:42, Russell Coker wrote: On Sat, 5 Dec 2015 12:08:58 AM Austin S Hemmelgarn wrote: I know that there are no plans to backport things to 3.16 and I don't think the Debian people are going to be very interested in this. So this message is a FYI for users, maybe consider

Re: 3.16.0 Debian kernel hang

On 2015-12-04 09:26, Russell Coker wrote: On Sat, 5 Dec 2015 12:53:07 AM Austin S Hemmelgarn wrote: The only reason I'm not running Unstable kernels on my Debian systems is because I run some Xen servers and upgrading Xen is problemmatic. Linode is moving from Xen to KVM so I guess I should

Re: subvols and parents - how?

On 2015-12-09 05:53, Duncan wrote: > Christoph Anton Mitterer posted on Wed, 09 Dec 2015 05:36:37 +0100 as > excerpted: > >> On Fri, 2015-11-27 at 01:02 +, Duncan wrote: >> [snip snap] >>> #2 The point I was trying to make, now, to mount it you'll mount not a >>> native nested subvol, and not

Re: utils version and convert crash

On 2015-12-02 05:01, Duncan wrote: Gareth Pye posted on Wed, 02 Dec 2015 18:07:48 +1100 as excerpted: Output from scrub: sudo btrfs scrub start -Bd /data [Omitted no-error device reports.] scrub device /dev/sdh (id 6) done scrub started at Wed Dec 2 07:04:08 2015 and finished after

Re: compression disk space saving - what are your results?

On 2015-12-02 04:46, Tomasz Chmielewski wrote: What are your disk space savings when using btrfs with compression? I have a 200 GB btrfs filesystem which uses compress=zlib, only stores text files (logs), mostly multi-gigabyte files. It's a "single" filesystem, so "df" output matches "btrfs

Re: Very various speed of grep operation on btrfs partition

On 2015-12-06 22:32, Duncan wrote: FWIW, I build kde without the semantic-desktop stuff even enabled at build-time (gentoo offers that option) here. All the kdepim stuff (kmail, etc) uses it, so I dumped the several kdepim related apps (kmail, akregator, kaddressbook) I used here and found

Re: Subvolume UUID, data corruption?

On 2015-12-05 07:01, Hugo Mills wrote: On Sat, Dec 05, 2015 at 04:28:24AM +0100, Christoph Anton Mitterer wrote: On Fri, 2015-12-04 at 13:07 +, Hugo Mills wrote: I don't think it'll cause problems. Is there any guaranteed behaviour when btrfs encounters two filesystems (i.e. not talking

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-15 09:42, Hugo Mills wrote: On Tue, Dec 15, 2015 at 09:27:12AM -0500, Austin S. Hemmelgarn wrote: On 2015-12-15 09:18, Hugo Mills wrote: On Tue, Dec 15, 2015 at 08:54:01AM -0500, Austin S. Hemmelgarn wrote: On 2015-12-14 16:26, Chris Murphy wrote: On Mon, Dec 14, 2015 at 6:23 AM

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-13 19:27, Christoph Anton Mitterer wrote: On Fri, 2015-12-11 at 16:06 -0700, Chris Murphy wrote: For anything but a new and empty Btrfs volume What's the influence of the fs being new/empty? this hypothetical attack would be a ton easier to do on LVM and mdadm raid because they

Re: dear developers, can we have notdatacow + checksumming, plz?

On 2015-12-13 23:59, Christoph Anton Mitterer wrote: (consider that question being asked with that face on: http://goo.gl/LQaOuA) Hey. I've had some discussions on the list these days about not having checksumming with nodatacow (mostly with Hugo and Duncan). They both basically told me it

Re: btrfs: poor performance on deleting many large files

On 2015-12-12 17:15, Christoph Anton Mitterer wrote: On Sat, 2015-11-28 at 06:49 +, Duncan wrote: Christoph Anton Mitterer posted on Sat, 28 Nov 2015 04:57:05 +0100 as excerpted: Still, specifically for snapshots that's a bit unhandy, as one typically doesn't mount each of them... one

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

<chan...@linux.vnet.ibm.com> Tested-by: Austin S. Hemmelgarn <ahferro...@gmail.com> I've read the discussions around the change and from the user's POV I'd suggest to add another mount option that would be just an alias for any mount options that would implement the 'hard-ro' semant

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-16 07:34, Christoph Anton Mitterer wrote: On Wed, 2015-12-16 at 07:12 -0500, Austin S. Hemmelgarn wrote: I kind of agree with Christoph here. I don't think that noload should be the what we actually use, although I do think having it as an alias for whatever name we end up using

Re: dear developers, can we have notdatacow + checksumming, plz?

On 2015-12-14 22:15, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 09:16 -0500, Austin S. Hemmelgarn wrote: When one starts to get a bit deeper into btrfs (from the admin/end- user side) one sooner or later stumbles across the recommendation/need to use nodatacow for certain types

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-14 16:26, Chris Murphy wrote: On Mon, Dec 14, 2015 at 6:23 AM, Austin S. Hemmelgarn <ahferro...@gmail.com> wrote: Agreed, if yo9u can't substantiate _why_ it's bad practice, then you aren't making a valid argument. The fact that there is software that doesn't handle it well

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-14 18:34, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 15:20 -0500, Austin S. Hemmelgarn wrote: On 2015-12-14 14:44, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 14:33 -0500, Austin S. Hemmelgarn wrote: The traditional reasoning was that read-only meant that users

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-09 16:48, S.J. wrote: >> 1. better practices, we really need to tell users, and documentation >> writers, that using dd (or variant) to copy Btrfs volumes has a >> consequence and should not be used to make copies. > >> 2. Btrfs needs a better way to make a copy of a volume when there

Re: subvols and parents - how?

On 2015-12-09 22:56, Duncan wrote: > Austin S Hemmelgarn posted on Wed, 09 Dec 2015 14:04:06 -0500 as > excerpted: > >> Agreed. It's not too bad fixing a Gentoo system (as long as >> /var/lib/portage/world is still correct, you can just nuke the installed >> packag

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-14 14:44, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 14:33 -0500, Austin S. Hemmelgarn wrote: The traditional reasoning was that read-only meant that users couldn't change anything Where I'd however count the atime changes to. The atimes wouldn't change magically

Re: btrfs: poor performance on deleting many large files

On 2015-12-14 14:39, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 09:24 -0500, Austin S. Hemmelgarn wrote: Unless things have changed very recently, even many modern systems update atime on read-only filesystems, unless the media itself is read-only. Seriously? Oh... *sigh*... You

Re: Still not production ready

On 2015-12-14 14:08, Chris Murphy wrote: On Mon, Dec 14, 2015 at 5:10 AM, Duncan <1i5t5.dun...@cox.net> wrote: Qu Wenruo posted on Mon, 14 Dec 2015 15:32:02 +0800 as excerpted: Oh, my poor English... :( Well, as I said, native English speakers commonly enough mis-negate... The real issue

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

On 2015-12-14 14:16, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 12:50 -0500, Austin S. Hemmelgarn wrote: It should also imply noatime. I'm not sure how BTRFS handles atime when mounted RO, but I know a lot of old UNIX systems updated atime even on filesystems mounted RO, and I know

Re: [PATCH v3] btrfs: Introduce new mount option to disable tree log replay

se_options() need to check new flags at remount time, so add a new parameter for parse_options(). Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chan...@linux.vnet.ibm.com> Tested-by: Austin S. Hemmelgarn <ahferro...@gmail.com> I've read the discu

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-14 19:08, Christoph Anton Mitterer wrote: On Mon, 2015-12-14 at 08:23 -0500, Austin S. Hemmelgarn wrote: The reason that this isn't quite as high of a concern is because performing this attack requires either root access, or direct physical access to the hardware, and in either case

Re: attacking btrfs filesystems via UUID collisions?

On 2015-12-15 09:18, Hugo Mills wrote: On Tue, Dec 15, 2015 at 08:54:01AM -0500, Austin S. Hemmelgarn wrote: On 2015-12-14 16:26, Chris Murphy wrote: On Mon, Dec 14, 2015 at 6:23 AM, Austin S. Hemmelgarn <ahferro...@gmail.com> wrote: Agreed, if yo9u can't substantiate _why_ it's bad pr

Re: device removal seems to be very slow (kernel 4.1.15)

On 2016-01-05 08:04, David Goodwin wrote: Using btrfs progs 4.3.1 on a Vanilla kernel.org 4.1.15 kernel. time btrfs device delete /dev/xvdh /backups real13936m56.796s user0m0.000s sys 1351m48.280s (which is about 9 days). Where : /dev/xvdh was 120gb in size. OK, based on the

Re: Replace a corrupted block using a known-good file from another filesystem ?

On 2016-01-05 07:25, Sylvain Joyeux wrote: In the course of the few btrfs crashes I had on my USB backup drive (NOT the drive from my other bug report, which is an internal SATA drive) - in the last 6 months or so - I ended up having a 4 to 5 bad checksums reported by scrub. This drive is used

Re: btrfs check inconsistency with raid1, part 1

On 2015-12-22 05:23, Duncan wrote: Kai Krakow posted on Tue, 22 Dec 2015 02:48:04 +0100 as excerpted: I just wondered if btrfs allows for the case where both stripes could have valid checksums despite of btrfs-RAID - just because a failure occurred right on the spot. Is this possible? What

Re: dear developers, can we have notdatacow + checksumming, plz?

On 2015-12-16 21:09, Christoph Anton Mitterer wrote: On Tue, 2015-12-15 at 11:00 -0500, Austin S. Hemmelgarn wrote: Well sure, I think we'de done most of this and have dedicated controllers, at least of a quality that funding allows us ;-) But regardless how much one tunes, and how good

Re: dear developers, can we have notdatacow + checksumming, plz?

On 2015-12-22 04:12, Duncan wrote: Austin S. Hemmelgarn posted on Mon, 21 Dec 2015 08:36:02 -0500 as excerpted: On 2015-12-16 21:09, Christoph Anton Mitterer wrote: On Tue, 2015-12-15 at 11:00 -0500, Austin S. Hemmelgarn wrote: nodatacow only [avoids fragmentation] if the file is pre

Re: Ideas on unified real-ro mount option across all filesystems

On 2015-12-21 20:32, Kai Krakow wrote: Am Fri, 18 Dec 2015 03:01:06 +0100 schrieb Christoph Anton Mitterer : The manpage says: ro Mount the filesystem read-only. rw Mount the filesystem read-write. That means: the filesystem... Not the block device... No, that

Re: [PATCH v4 1/2] btrfs: Introduce new mount option backuproot to replace recovery

ovides the basis for later unified "norecovery" mount option. Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com> --- v4: Newly introduced to avoid confusion with later 'norecovery' patch. --- I ran my usual tests overnight on this part, and nothing broke, so you can add Tested-by

Re: [PATCH v4 1/2] btrfs: Introduce new mount option backuproot to replace recovery

On 2015-12-22 07:30, Holger Hoffstätte wrote: On Tue, Dec 22, 2015 at 3:16 AM, Qu Wenruo wrote: Current "recovery" mount option will only try to use backup root. However the word "recovery" is too generic and may be confusing for some users. Here introduce a new and

Re: btrfs send reproducibly fails for a specific subvolume after sending 15 GiB, scrub reports no errors

On 2015-11-24 15:50, Christoph Anton Mitterer wrote: On Tue, 2015-11-24 at 15:44 -0500, Austin S Hemmelgarn wrote: I would say it's currently usable for one-shot stuff, but probably not reliably useable for automated things without some kind of administrative oversight. In theory, it wouldn't

Re: btrfs check help

On 2015-11-24 12:06, Vincent Olivier wrote: Hi, Woke up this morning with a kernel panic (for which I do not have details). Please find below the output for btrfs check. Is this normal ? What should I do ? Arch Linux 4.2.5. Btrfs-utils 4.3.1. 17x4TB RAID10. You get bonus points for being on a

Re: shall distros run btrfsck on boot?

On 2015-11-24 12:23, Christoph Anton Mitterer wrote: On Tue, 2015-11-24 at 11:14 -0600, Eric Sandeen wrote: In a nutshell, though, I think a filesystem repair should be an admin-initiated action, not something that surprises you on a boot, at least for a journaling filesystem which is designed

Re: [PATCH v2 1/5] btrfs-progs: introduce framework to check kernel supported features

On 2015-11-24 09:39, Mike Fleetwood wrote: On 23 November 2015 at 12:56, Anand Jain wrote: In the newer kernel, supported kernel features can be known from /sys/fs/btrfs/features however this interface was introduced only after 3.14, and most the incompatible FS

Re: btrfs send reproducibly fails for a specific subvolume after sending 15 GiB, scrub reports no errors

On 2015-11-24 13:48, Christoph Anton Mitterer wrote: Hey. All that sounds pretty serious, doesn't it? So in other words, AFAIU, send/receive cannot really be reliably used. I did so far for making incremental backups, but I've also experienced some problems (though not what this is about

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