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

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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)?
4
votes
1answer
423 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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74 views

How to delete a directory with multiple btrfs subvolumes?

My root file system is on a btrfs partition. My /chroot directory has a number of btrfs subvolumes in it which prevent me from deleting it with rm -rf /chroot. In an attempt to delete all the ...
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594 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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49 views

BTRFS has become unmanageable

I'm struggling with a btrfs RAID0 filesystem. It's expanded on 4 disks but i need to remove one of those disks. This is the current status of the filesystem: [root@osgiliath detlev]# btrfs fi show ...
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118 views

BTRFS: too many missing devices, writeable mount is not allowed

Environment $ btrfs --version btrfs-progs v4.2.1 $ uname -a Linux [REDACTED] 4.2.1-040201-generic #201509211431 SMP Mon Sep 21 18:34:44 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux Problem Today the ...
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28 views

Can I determine the exclusive space usage of groups of btrfs subvolumes?

I want to free up some space in my btrfs filesystem by deleting some snapshots. But I cannot work out which ones would be effective to delete. This question's answer explains how to show the amount of ...
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46 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?
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228 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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175 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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76 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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122 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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39 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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249 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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162 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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46 views

Copy remote btrfs incremental snapshot to new drive w/ UUID

Situation: Two machines (A & B, with local drives dA & dB) connected via slow network. Drive dA has initial backup to dB, while locally attached on machine A. btrfs send RO-snapshot-1-dA | ...
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23 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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21 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 ...
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227 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 ...
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81 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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64 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?
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94 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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152 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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574 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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450 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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3 views

Btrfs: available space not used after migrating from RAID1 to RAID6

I had 8 2TB disks running in a RAID1 setup but it started to get full so I converted it to a RAID6. However, it seems I can't use the space I've gained by switching to RAID6. My filesystem is pretty ...
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11 views

Snapper - how to undo changes, preserving timestamps?

I've damaged modification dates of files on my drive and I wanted to revert them using snapper snapshots but it doesn't seem to work, snapper only reverts content of files not modification dates. ...
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20 views

BTRFS reports errors, but the drives don't. Do I have failed drives?

I have been using btrfs for over a year, and noticed reports of lots of errors in the logs but no problems. A recent scrub found HUGE numbers of csum errors, by huge I mean 85 MILLION, however scrub ...
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34 views

Udisks2, LUKS and btrfs

I just bought a portable USB HDD,on which i put 2 partitions : a LUKS one, which contains a btrfs fs and a fat32 one, in case I'd have to use a system which doesn't support LUKS or btrfs I use ...
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215 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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69 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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49 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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330 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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81 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. ...
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32 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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373 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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108 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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282 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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53 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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62 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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16 views

btrfs - how to list files stored in a block?

I have some troubles with my btrfs file system on Ubuntu (my partition automatically enter in read-only mode after the login screen). I would like to know if one can know which files are included in ...
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0answers
11 views

btrfs shrinked after failed balance

I have a btrfs on a 2TB disk. According to btrfs fi show, less than half of the space is used: Label: 'photo' uuid: cccecc10-da2c-4fd6-ae38-31d160dfb6df Total devices 1 FS bytes used 753.21GiB ...
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45 views

btrfs balance memory requirements?

I'm trying to rebalance data on my btrfs filesystem to free up some (a lot) of disk space. However, my machine consistently keeps OOMing itself into death. Currently I'm assigning 1.5 GB of RAM but ...
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60 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 ...
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52 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 ...
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188 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 ...
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37 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 ...
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66 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 ...
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303 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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297 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 ...