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

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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 ...
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1answer
32 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
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1answer
524 views

Access files from BTRFS image on similar filesystem

Backgroud: Running XBian (Debian ARM distribution for Raspberry Pi), which uses BTRFS. I fragged my system and decided to start over. However, I ripped the image from the root filesystem device before ...
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1answer
49 views

fs synchronization among desktops

I have several workstations (laptops and desktops). I'd like to synchronize files among them such that each one is a mirror of the other. I used to run an NFS server and share files out, but that ...
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1answer
97 views

Why does ZFS large file not instantly like btrfs?

Copying a 1TB disk image on a btrfs partition with cp takes less than a second on my Ubuntu 14.10 amd64 with Linux 3.16.0. Why does it take at least 5 minutes and requires > 1 GB to be read on a ZFS ...
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1answer
541 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 ...
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1answer
35 views

CROSS compilation of BTRFS file system

We are developing Beaglebone black based custom board, We are planing to use eMMC for storage. To decide the file system on the eMMC we want to cross compile Btrfs user space utility, Does anyone know ...
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97 views

btrfs: mismatching generation and generation_v2 found in root item

I am seeing this message in dmesg: btrfs: mismatching generation and generation_v2 found in root item I found a related question here: Understanding btrfs dmesg However, unlike that question, I ...
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51 views

ideal btrfs storage scheme to incorporate external USB HDD as backup media

Is there a way to leverage btrfs's advanced features (COW, snapshots, etc.) to continuously backup/mirror my main storage volume to an external USB HDD?
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458 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 ...
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166 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 ...
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26 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 ...
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197 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 ...
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141 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 ...
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20 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 ...
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0answers
8 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 ...
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28 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 ...
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63 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 ...
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0answers
209 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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350 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 ...
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20 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 ...
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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 ...
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219 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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119 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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170 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 ...
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38 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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53 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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170 views

Understanding btrfs disc usage for single data volume

On my 256 GB disc: # btrfs fi show /dev/sdd3 Total devices 1 FS bytes used 143.43GiB devid 1 size 234.22GiB used 234.22GiB path /dev/sdd3 Btrfs v3.12 I don't understand the discrepancy between ...
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26 views

Defrag range ioctl not supported in this kernel, please try without any options

I'm trying to compress my BTRFS filesystem for all the files I added before adding compress=lzo to /etc/fstab. I've booted into a live CD and run the following: sudo mount /dev/mapper/root /mnt sudo ...
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130 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 ...