A copy-on-write (COW) file system developed by Oracle included in the Linux kernel.

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6
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1answer
393 views

Is btrfs suitable as backup filesystem?

Right now I have a pretty traditional backup filesystem structure on top of ext4. Every time a backup is made, a new folder backup-DATE is created to which files are rsync'ed (with hardlinks made ...
3
votes
1answer
3k views

Clear unused space with zeros (btrfs)

How to clear unused space with zeros ? (I am asking for tool for btrfs filesystem) I'm looking for something smarter than cat /dev/zero > /mnt/X/big_zero ; sync; rm /mnt/X/big_zero Like ...
2
votes
1answer
82 views

Is there a simple way to move btrfs subvolumes to a different btrfs filesystem?

I have two separate btrfs filesystems which I would like to consolidate. The subvolume structure looks like this: / filesystemA |- subvolume1 |- subvolume2 |- ... |- subvolumeN / filesystemB |- ...
2
votes
1answer
52 views

Will send & receive also defragment data?

I have heavily fragmented (and 90% full) btrfs partition on my laptop. I'd like to perform defragmentation with the help of identical spare hard drive. I already re-created partition table (GPT) and ...
2
votes
1answer
43 views

How to free up space on non-responsive full btrfs system?

I copied files to a btrfs raid-1, which turned out not to fit. When the drives became full, they also became unresponsive. ls [directory], never finishes. I tried rm ...
2
votes
1answer
731 views

Docker - Force to Use AUFS Instead of BTRFS

I am having significant problems using Docker on my BTRFS filesystem, and I suspect that is due to a lack of stability with the BTRFS driver. I would rather figure out how to switch the fs driver than ...
4
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0answers
83 views

How do I view the btrfs checksum of a file?

Btrfs calculates a crc32c checksum for each file. Is there a way I can view what checksum is stored (as opposed to just reading the file and recalculating it)?
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0answers
547 views

Compiling and running Snapper for Ubuntu

I am trying to get snapper working in my Mint 14. (The version from launchpad is old and not compatible with Ubuntu 12.10. The OpenSuSe's build project failed to build it, too). So I try my luck with ...
3
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0answers
36 views

How to find the amount of shared extents on btrfs?

What command can I use to see the amount of shared extents on a btrfs volume. Or better yet, what command gives me the logical size used along with the on-disk size of all extents together?
3
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0answers
158 views

Running a btrfs RAID 5 array on Arch Linux

For two weeks, I've been trying to run my Raspberry Pi (model B) as root from a btrfs RAID 5 without success. The RAID runs on three 1TB disks /dev/sda, /dev/sdb and /dev/sdc. The three disks were ...
3
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0answers
74 views

List all btrfs filesystems and subvolumes in shell

Is there a convenient way to get information on all btrfs filesystems subvolumes without resorting to C, i.e. in POSIX shell ? /sys/fs/btrfs contains info only on filesystems, nothing on subvolumes, ...
3
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0answers
41 views

Configure where GRUB2 environment block is located

I have Arch, Ubuntu, and GRUB2 installed on a BTRFS filesystem. I'm aware that GRUB cannot write to BTRFS for a variety of good reasons, and therefore cannot save environment variables to ...
3
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0answers
35 views

How much space would be freed by removing a btrfs subvolume?

Is there any way to calculate how much space I would free if I would remove one (or several) subvolumes on a Btrfs disk (without actually removing them)? I know that there is "currently no code that ...
3
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0answers
234 views

LXC with both GUI apps and snapshots on unmodified Fedora kernel

I am looking for a tool or library to run LXC that supports: running X applications conveniently snapshotting root filesystems (using a Fedora system with an unmodified kernel), so that I don't have ...
3
votes
0answers
151 views

How does SuSE Linux's support for btrfs differ from Ubuntu and Fedora's?

The SuSE Linux Enterprise Server 11 Service Pack 2 release notes state that SuSE offers "commercial support" for btrfs, while Ubuntu and Fedora appear to be holding back until a working fsck utility ...
2
votes
0answers
12 views

Modifying a file “pointed” to by a lot of snapshots

I'm using btrfs and snapper. So, I have many periodic btrfs snapshots, which are marked read-only (can of course be changed by btrfs to r/w and changed back.) Let's say during my initial install I ...
2
votes
0answers
127 views

Restore Btrfs snapshot from subdirectory to parent

I have a Btrfs partition which has a single subvolume at the top level (/root). It has subvol=root option in /etc/fstab. Every week, I take a readonly snapshot into /root/snapshots/... using: btrfs ...
2
votes
0answers
51 views

What can I do with btrfs “profiles”?

Reading through the btrfs (sub) command documentation, it can "balance only block groups with the given replication profiles", and "convert selected blocks to a given profile", and apparently it ...
2
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0answers
44 views

Btrfs: Is there an easy way to find a file by block numbers it occupies?

Say, you have filesystem Btrfs formatted, then you, all of the sudden as it happens, wonder — what files occupy blocks #356 and #789, how you gonna answer this question?
2
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0answers
75 views

How do I layer compression on top of encryption on top of BtrFS, per-file?

BtrFS should support this really, but it doesn't. So ECryptFS looks like it will fill the gap. The only thing is, how would I layer compression on top of this? Reasons for compression on top of ...
2
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0answers
81 views

On which disk is a file located in a btrfs RAID-1 array/filesystem?

I have a btrfs array with 5 disks in RAID-1 mounted on /mnt/array: # btrfs filesystem show /mnt/array Label: 'nicefilesystem' uuid: censored Total devices 5 FS bytes used 4.95TiB ...
2
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0answers
71 views

BTRFS - Raid incomplete after balancing

I have two 3TB drive that are formated as btrfs and mounted on /media/andy/btrfs as one drive. I run btrfs balance start -dconvert=raid1 -mconvert=raid1 /media/andy/btrfs/ which takes forever. It ...
2
votes
0answers
120 views

How do I align my new btrfs default subvolume with the real root of my filesystem?

I rolled back my system by using snapper rollback Unfortunately this caused my current default volume to not be at the root of my filesystem anymore. As you can see in this screenshot: The ...
2
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0answers
395 views

“cache and super generation don't match, space cache will be invalidated” what does this means and how to repair it?

I'm having a little problem trying to grow a btrfs partition in my system, namely: sudo btrfsck /dev/sdb9 [sudo] password for braiam: Checking filesystem on /dev/sdb9 UUID: ...
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409 views

System cannot boot, continiously scanning btrfs filesystem

On the previous boot I installed HAL to make amazon prime video streaming work, which it did (mostly), but after reboot the system could not pull itself up all the way to BASH and drops to a failed ...
1
vote
0answers
8 views

List reflink filenames to a file on btrfs

Given a path/filename on a btrfs filesystem, how can you see the other reflinked path/filenames to the same file?
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0answers
31 views

BTRFS RAID6 array is broken, how do I fix it?

I have a server running a btrfs raid 6 array which seems to have broken. When try to mount it I get the following error message. I don't know how or why it broke maybe a power outage or something (it ...
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0answers
25 views

Does this bug indicate an error in my btrfs filesystem of simply a bug in the 4.2.0-RC5 kernel?

I'm not sure this is the right place to ask this... I have been running a pre-release kernel (4.2.0-rc5) and yesterday had a possible disk error on my 6-disk raid-1 btrfs filesysystem. While trying ...
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0answers
25 views

btrfs device add: different mount options than for seed?

I have a btrfs seed device, created with mixed data+metadata (mkfs.btrfs --mixed), and also --metadata single. This device is read-only. When doing btrfs add device /dev/sdc1 /mnt, is it possible to ...
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0answers
114 views

ssd caching in loop device on btrfs

I have an ssd and 2TB hard disk. The ssd is used for the root filesystem which uses only around 20G of the 120G available. Is there a way to use an image/loop on the root filesystem (btrfs) as a cache ...
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0answers
37 views

btrfs - snapshot of a parent subvolume excludes child subvolumes?

Let's say I want to exclude ever-changing logfiles from backups. Parent subvolume / Child subvolume /log I snapshot /. Looking at the snapshot, /.snapshots/today/log will be empty, correct? This is ...
1
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0answers
35 views

BTRFS - removing drive by devid instead of path

I recently lost a 5 TB drive using btrfs. I had a system freeze (unsure why) while a balance was running. My SMR drive got corrupted. I was able to mount my array degraded and balance my data. ...
1
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0answers
28 views

Formatting btrfs for robust metadata

If I make three partitions on a HDD, it appears that the default (which is -m raid1) will only store two copies of each metadata block. Is there a way to store multiple copies, e.g. one on each ...
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0answers
186 views

How does enabling btrfs quotas impact the system?

I use btrfs snapshots quite a bit, and one of the things that interests me is how much space a given snapshot takes up - or to be more specific - how much exclusive data a btrfs snapshot is taking up, ...
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0answers
69 views

When using btrfs, why “Size”, “Used” and “Avail” values from df do not match?

I have similar problem like unix.stackexchange.com/questions/37489/ btrfs filesystem show Label: none uuid: 3fdeaf6d-ca88-4cc8-8405-f882f02693f7 Total devices 3 FS bytes used 1.53MB devid ...
1
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0answers
318 views

btrfs balance fails due to enospc error

[taken over from stackoverflow since I figured that was probably the wrong place] I am currently testing btrfs as a possible replacement for my NAS running ZFS. I created 4 devices, 20GB each, and ...
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0answers
239 views

How to run SSD trim fstrim on btrfs when mounted multiple subvolumes?

I am using btrfs and have mounted several subvolumes (but not btrfs root). It resides on SSD partition, so I would like to use fstrim. Should I call fstrim on each mountpoint (corresponding with ...
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0answers
218 views

Recover data from a BTRFS RAID5

I have a BTRFS RAID5 setup (no mdadm) with four disks (the fifth failed). Now I am trying to recover the files but as soon as I try to rsync the files over to another disk, the system hangs after ...
1
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0answers
44 views

btrfs partition not detected

I have some distros installed on a BTRFS partitions under different subvolumes ( for distro-hopping, separate ext4 boot). This btrfs partition is now not getting detected on boot, while I can access ...
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0answers
59 views

What are the linux kernel versions incompatibilities with btrfs?

I read that usage of a btrfs volume with a newer kernel can render it unreadable when that same volume is used with an older kernel. I have a mobile storage device that will be used by different linux ...
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0answers
13 views

How to know perfect filesystem parameters for flash drive format

I have a flash drive and using btrfs on it with default parameters. And now I'm going to slightly improve read/write speed. I see that "play the game" with page and sector size can helps me. But ...
0
votes
0answers
14 views

Will btrfs snapshots ever share page cache?

It's common to run multiple container images based on the same parent. In theory you should be able to share page cache between these containers automatically. E.g. some of the code in shared ...
0
votes
0answers
16 views

How to throttle system resources during transfer from btrfs on file image on cifs mount?

I have a btrfs on a sparse file image (4TB) on a cifs mount of a remote NAS (Synology DS214) with zlib compression enabled. Transferring file from and onto the btrfs causes freezes of Linux (where it ...
0
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0answers
34 views

where to compress=lzo, btrfs with virtual disk images, with their vm's internally using btrfs

I've been using compress=lzo on my btrfs volumes, because I read this fast compression method actually increases drive performance. (Haven't tested myself.) I'm starting to use ...
0
votes
0answers
17 views

btrfs scrub history disappeared

I had some corruption on a multi-disk RAID1 scrub setup and was running the command: watch -n10 -d ;btrfs file usage -T -g /mnt/b;echo;btrfs scrub status -d /mnt/b' After the scrub finished, I ...
0
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0answers
26 views

Display btrfs subvolume tree

Is there a way to make a btrfs subvolume tree like what is shown below? (Only subvolumes - no regular directories or files.) # tree /mnt/1 /mnt/1 ├── a ├── snapshot │ ├── a │ └── subv └── subv ...
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0answers
33 views

Whats the right way of Data/Subvolume structure/hierarchy management using btrfs

My intention is to switch my filesystem from ext4 to btrfs. Currently I have 2 space disks with 4 TB each. I allready set them up in raid1 (using mkfs.btrfs -d raid1 /dev/sdx /dev/sdy) Then there ...
0
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0answers
151 views

Mount BTRFS on Android (usb OTG)

I am using btrFS as a filesystem for my external harddrive. I'd like to use it under Android. Is there any painless way to do so?
0
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0answers
160 views

encrypted btrfs RAID1 array fails to mount at boot - open_ctree_failed

I have an encrypted btrfs RAID1 array set up as my /home directory on a fresh install of Linux Mint 17.1. At the Plymouth screen during boot, I enter my password for the two drives, and then receive ...
0
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0answers
201 views

BTRFS Raid1 on SD card and HDD

I have the / partition on a btrfs SD card /dev/mmcblk0p2. /boot is on vfat /dev/mmcblk0p1). It's a Raspberry Pi running Arch Linux and its fstab looks like so: /dev/mmcblk0p2 / btrfs ...