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

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Mounting failed - invalid argument

I've setup a Kali Linux installation on an SD card and created an encrypted LUKS partition with a LVM logical volume inside of it, then created a BTRFS filesystem inside. Almost everything works, but ...
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33 views

Can you uncompress a btrfs filesystem?

I found out that you can compress the whole of a Btrfs filesystem by defragmenting it with -clzo or -czlib, but is it possible to uncompress it again? I'm asking because I managed to stop my system ...
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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. ...
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43 views

Abysmal general dm-crypt (LUKS) write performance

I am investigating a problem where encrypting a block device imposes a huge performance penalty when writing to it. Hours of Internet reading and experiments did not provide me with a proper ...
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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?
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Can't boot, task btrfs-transacti blocked for more than 120 seconds, how to fix this?

My computer was set up to boot Ubuntu 15.04 via UEFI. I have two disks. My first disk /dev/sda is a 128 GB ssd formatted as GPT, containing an EFI partition and a btrfs partiton with subvolume @ ...
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21 views

Deduplication semantics with btrfs - meta-data differs, file data identical

So I read this Wiki article on deduplication with btrfs. However, it doesn't describe the semantics followed by btrfs deduplication. Assume you have a dozen files. They all contain identical data, ...
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25 views

use git to update my local copy with latest btrfs-progs

This is hopefully a very simple git question but I haven't been able to find the answer, most info about git assumes you want to upload and merge changes and my situation is much simpler than this. I ...
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24 views

How to get error detection and correction on a single hard drive on linux (with btrfs or other methods)

One of the cool things about btrfs on linux is that it can correct bit rot if it has redundant data because of its per-block checksumming. I can get redundant data by setting up a raid1 with two ...
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84 views

Why does btrfs refuse to convert metadata to RAID1

I created a single-device btrfs filesystem. According to the btrfs wiki article on using multiple devices, I should be able to convert that to RAID1 using: btrfs balance start -dconvert=raid1 ...
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126 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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42 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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42 views

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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25 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 ...
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27 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
51 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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208 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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36 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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18 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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52 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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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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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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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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155 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: 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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88 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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87 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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114 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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49 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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135 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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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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94 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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59 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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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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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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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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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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420 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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152 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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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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209 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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660 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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1answer
136 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
658 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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923 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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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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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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917 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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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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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? ...