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

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How to list files part of a BTRFS block?

On my BTRFS filesystem, I have a problem with block id #43231330304. BTRFS critical (device sda2): corrupt leaf, slot offset bad: block=43231330304,root=1, slot=47 I want to know which files are ...
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58 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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48 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 ...
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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 ...
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1answer
33 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 ...
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1answer
614 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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62 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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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 ...
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18 views

Create subvolume on non-mounted filesystem

I'm working on automating creation of BTRFS filesystems for my purposes in the cloud. The process is a little annoying to be honest, and I'd like to cut out a few steps in the process. My process ...
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1answer
76 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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247 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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35 views

How to repair a BTRFS block?

For some unknown reasons, my BTRFS filesystem is corrupted. dmesg prints BTRFS critical (device sda2): corrupt leaf, slot offset bad: block=43231330304,root=1, slot=47 (more than 1000x in the dmesg ...
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1answer
139 views

How do I figure out what's freezing up my machine?

I am running Arch on this machine: 3.40GHz i7 hexacore (4930K) 16GB DDR3 1600MHz RAM 2xSamsung 840 EVO SSDs in Raid0 (using BTRFS raid) When I run VMware on my Arch with a few VMs (2 ...
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2answers
31 views

Matching btrfs documentation for the version I have?

I want to see if the formatting details I specified are doing what I thought, and generally inspect things after a huge amount of copying to the btrfs file system. Looking through docs, I see btrfs ...
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16 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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4answers
7k views

How to get rid of the “scanning for btrfs file systems” at start-up?

After upgrading from Ubuntu 12.04 to Ubuntu 12.10, I get a message "scanning for btrfs file systems" at starting-up. I don't have any BTRFS filesystem. It delays the booting for about 15 seconds. How ...
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27 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?
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116 views

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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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?
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44 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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34 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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100 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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242 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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45 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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49 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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41 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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3answers
999 views

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
74 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
29 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
59 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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45 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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37 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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19 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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46 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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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) ...
3
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1answer
106 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?
3
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2answers
260 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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1answer
180 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 ...
2
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1answer
501 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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2answers
515 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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46 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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637 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
583 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
624 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% ...
2
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1answer
34 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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47 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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4answers
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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222 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? ...