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

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btrfs RAID1 array shows as two disks

I mounted 2 drives as a RAID1 btrfs array (btrfs v3.12, Ubuntu 14.04). Everything's working fine except nautilus and other GUI-based apps see two disks, both labeled "Raid1". One is mounted (the ...
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18 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, ...
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27 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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75 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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1answer
2k 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 ...
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203 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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17 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 ...
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26 views

btrfs: mounting a subvolume in a different path does not work - No such file or directory

I want to mount the subvolume in a different directory on the @ subvolume... should be possible or did I miss something? # btrfs subvolume create /foo # mkdir -p /mnt/storage1/foo # mount -t btrfs ...
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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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35 views

How to check (simulate), how much space will be freed after I remove a btrfs subvolume?

The question is not trivial. BTRFS is COW file system and one object stored on hard disk can be referenced by many files. I use BTRFS snapshots as a part of a backup solution on my production ...
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1answer
566 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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Why can't a regular user delete a btrfs subvolume

Using a loop-mounted user created btrfs filesystem, with the permissions set correcly, a user is able to freely create btrfs subvolumes: user@machine:~/btrfs/fs/snapshots$ /sbin/btrfs sub create ...
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1answer
52 views

systemd mount 'rootfs' according to '/proc/cmdline'

SETUP Im running Debian 8 (jessie/testing) amd64 with systemd. On my system partition containing a btrfs filesystem, I do have the following layout: /dev/sda1 |-root |-root_snapshots/ ...
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1answer
19 views

How to delete btrfs subvolume?

I have a snapshot that I'd like to delete: 04:03:21::mlissner@pounamu::~ ↪ sudo btrfs subvolume list / ID 257 gen 267078 top level 5 path @badroot ID 258 gen 267151 top level 5 path @home ID 422 gen ...
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1answer
30 views

Creating a btrfs subvolume mounted under another file system

At the moment I have a / partition with btrfs and /home partition with xfs. I would like to take advantage of btrfs snapshots for certain directories under /home, e.g. /home/robert/.wines . Apparently ...
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50 views

Can BTRFS stripe RAID arrays?

I've been using an Ext3/4+lvm2+mdadm file system setup for about 5 years on a file server. This has grown (and moved processors a couple of times) and I've moved disks between systems ...
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1answer
36 views

Can you do a btrfs snapshot of a live system?

I am planning on giving btrfs a try soon, and what I want to know, and can't seem to find online is this: Can you do a btrfs snapshot on a running system if the snapshot is not just of some small ...
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3answers
2k views

How to remove an empty directory (btrfs filesystem)?

I'm using the experimental btrfs filesystem. My directory looks like this: ls -la empytfolder total 4 drwxr-xr-x 1 root root 0 19. Mär 14:00 . drwxr-xr-x 1 root root 298 19. Mär 13:59 .. I ...
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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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29 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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14 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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37 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 ...
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1answer
133 views

Clear all Snapper snapshots

OpenSUSE (among other distributions) uses snapper to take snapshots of btrfs partitions. Some people think the default snapshot intervals take up too much space too quickly, but whether or not you ...
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1k views

How to make a btrfs snapshot writable?

According to the btrfs Readonly snapshots patch it's possible to "set a snapshot readonly/writable on the fly." So I should be able to turn my readonly snapshot (created with btrfs snapshot -r) ...
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1answer
81 views

Mount options for BTRFS on an external USB drive

I've formatted my external HD with BTRFS (aware of the risks). What are options I should use to increase failure tolerance on sudden power loss to the drive?
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245 views

ext4 to btrfs conversion: If I accidentally lose power to the system during the conversion, will I lose the data?

I want to convert the 3TB 80% full ext4 block device into btrfs and I want to estimate the risks involved in the process. If I accidentally lose power to the system during the conversion, will I ...
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43 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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1answer
145 views

install with BTRFS: subvolume/partition scheme?

I'm fairly new to both GNU/Linux and btrfs, but I've decided I want to make my next computer (a desktop with one HDD) use Linux with btrfs as the filesystem. However, I've seen some advice online that ...
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1answer
371 views

Path `/boot/grub' is not readable by GRUB on boot. Installation is impossible. Aborting

Whenever I try updating grub, I get this error: # grub-install /dev/sda Path `/boot/grub' is not readable by GRUB on boot. Installation is impossible. Aborting. and # grub-mkconfig -o ...
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430 views

Slow access to btrfs on LVM/

We have this setup on our server: Ubuntu 14.04 (used to be 12.04) 10TB RAID-6 system LVM (one VG, two LV) ext4 partition ( ~2TB) Btrfs partition ( ~8TB) After a reboot last month the system was ...
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40 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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465 views

Resize a btrfs partition inside a logical LVM volume

Following derobert's trick to resize the underlying filesystem when resizing a LVM volume: lvm> lvextend -r -l +100%FREE /dev/VolGroup00/lvolhome fsck from util-linux 2.25.2 /sbin/fsck.btrfs: ...
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1answer
562 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
411 views

btrfs ERROR: error during balancing - No space left on device

My Kubuntu 12.04 system ran out of space on on the root partition and will not boot. The command df -h shows a lot of space available (with only 37% used): /dev/sda2 45G 17G 29G 37% ...
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1answer
33 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 ...
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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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2k views

Why is cp --reflink=auto not the default behaviour?

Why is cp --reflink=auto not the default behaviour? Could it cause any harm to enable it? Is it possible to enable it at compile time, so it is used all across the system, not just in interactive ...
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4answers
175 views

BTRFS data integrity (CRC32c) and HDD data integrity (sector ECC)

I'm new to BTRFS and I'm trying to understand why BTRFS use CRC32c while HDD already have sector level data integrity ECC. Is it because BTRFS don't relay on media to have data integrity protection? ...
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4answers
7k views

Should a laptop user switch from ext4 to btrfs?

Related to this. I'd like to take advantage of an OS switch to upgrade to BTRFS. BTRFS claims to offer a lot (data-loss resiliency, self-healing if RAID, checksumming of metadata and data, ...
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2answers
1k views

Arch does not mount btrfs array on boot

As data partition I have a multi-disk btrfs filesystem. My root disk is ext4 Fstab: UUID=290624c6-6b95-41fd-94a1-923ebca64b83 / ext4 rw,relatime,data=ordered 0 1 /dev/sdc ...
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1answer
103 views

run btrfs balance with cron

Since I run today in a problem with a full disk, which turns out is not unbalanced. Which you can fix with btrfs balance. So my question is: Is there any risk by ruining this by a cron job? (in ...
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1answer
196 views

Equivalent of pvmove for BTRFS

Similar to the question I asked a while back. This one's a little easier? I can see there's volume management logic in BTRFS for removing/adding/rebalancing physical drives, but is there a tool to ...
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603 views

Is partition table type “loop” a good or bad idea on BTRFS?

I have started to convert my disks to btrfs and following tutorials, most of them created the filesystem directly on the device instead on a partition. The file system is working and stores data but ...
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1answer
56 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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138 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 ...
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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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1answer
108 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
33 views

Is it possible and how to merge identical files between different snapshots in a btrfs file system?

I regularly use btrfs's snapshot to backup the whole system, but it's redundant to have identical files between different snapshots. Commonly, for example, I took a snapshot of @ as ...
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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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1k views

Why does my desktop lock up when I copy lots of files to a USB drive?

My desktop is usually very responsive, even under heavy load. But when I copy files to a USB drive, it always locks up after some time. By "lock up", I mean: Moving focus from one window to another ...