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

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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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47 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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1answer
220 views

How to install Debian Jessie properly onto multiple devices with BTRFS in mode RAID 1?

As a short introduction I'm going to tell you, what kind of setup I have and what I want to achieve. After that I try to explain my problem. Since this is my first question on U&L I have to ...
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128 views

Which file system (among XFS, BTRFS and EXT4 only) does provide the best data resilience to disk corruption? [closed]

Question: Given these three filesystems: XFS, BTRFS and EXT4, I'm wishing to know which does provide the best data resilience to data corruption in a setup without RAID. And, of course, why? ...
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1answer
46 views

Rolling back btrfs subvolume with child subvolumes

Is there a canonical way of rolling back to a subvolume snapshot that has child subvolumes. So for example, this is my btrfs volume layout: ID 257 gen 59802 top level 5 path __active ID 258 gen 59784 ...
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1answer
70 views

Simulate bitrot/corrupt files (for BTRFS)

Is it possible to intentionally corrupt a file so that BTRFS will report a checksum error? I want to test a script that's supposed to find file names with checksum errors, but I don't have any corrupt ...
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51 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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17 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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1answer
62 views

Why does the mountpoint of my root filesystem change?

When I look at the output of lsblk it will usually show: lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 298.1G 0 disk ├─sda1 8:1 0 1023M 0 part /boot └─sda2 8:2 0 ...
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1answer
289 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) ...
2
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1answer
64 views

What privileges are needed to delete a read-only btrfs subvolume?

I want to delegate non-root user to delete read-only subvolumes (snapshots). What exactly capabilities/rights I need to grant, so that he can remove his own read-only snapshots? I've already ...
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1answer
399 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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93 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 ...
9
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1answer
93 views

Limit on the number of btrfs snapshots?

I am considering using btrfs on my data drive so that I can use snapper, or something like snapper, to take time based snapshots. I believe this will let me browse old versions of my data. This would ...
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1answer
66 views

How reliable is (or will be) btrfs send/receive?

We have at work a 15TB NFS file server using XFS, with a distant clone for backups using rsync, over a moderately slow connection (100Mb ethernet). We are now thinking about using btrfs instead of ...
3
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1answer
59 views

Get device with major number 0 (btrfs subvolume)

When I stat a file on a btrfs subvolume I get a major device number of 0. Is there a reliable way to find the mount point of this device, without knowing in advance it is a btrfs subvolume? e.g. I'd ...
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1answer
50 views

btrfs confused about subvolumes

I'm starting out with btrfs on my embedded Linux system. My system currently has a single SD card used for the rfs. What I'd like to do is have a way to snapshot both the system files (currently ...
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1answer
146 views

What actually happens when the checksum fails for a file using btrfs?

I'm testing using btrfs on my embedded Linux system. It uses a uSD card for the rfs. This system is remotely deployed so there's no human sysadmin to take care of it. My question is what happens ...
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1answer
42 views

btrfs snapshots without subvolumes?

I'm starting to use btrfs. I want to be able to snapshot certain directories but do not want to create sub-volumes. Is this possible?
2
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1answer
172 views

btrfs on SD card, what does “Btrfs detected SSD devices, enabling SSD mode” mean exactly?

I'm experimenting with using btrfs on my Debian Linux armhf system. The rfs is on a micro SD card. On bootup I get the message "Btrfs detected SSD devices, enabling SSD mode". What features does ...
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2answers
67 views

Shrink btrfs from /dev/sda to /dev/sda1

suppose I have 2 btrfs filesystems: one mounted on /mnt/big spanning across /dev/sda /dev/sdb /dev/sdc /dev/sdd the other mounted on /mnt/small on a single drive: /dev/sde How would I shrink the ...
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2answers
100 views

Error when creating BTRFS Filesystem

I'm attempting to install Arch Linux using the btrfs filesystem. I'm at the beginning of the install processes preparing my drive and I'm hitting an issue. Firstly I begin to clear any GTP and MBR ...
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1answer
256 views

How to find data copies btrfs

I have deduplicated my btrfs filesystem with bedup, so now all duplicate files (above a certain size) are "reflink" copies. Is there any way to see, given a filename, what other files are the same ...
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1answer
110 views

ex4 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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21 views

ext4 to btrfs conversion: Can I pause, reboot the system and then resume the conversion? [duplicate]

I want to convert a rather big ext4 volume into btrfs. How long will the process will take?
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1answer
78 views

ext4 to btrfs conversion: how many times the whole volume will be read during the process?

I want to convert the 3TB 80% full ext4 block device into btrfs and I want to estimate the time it will take. I understand that this process is disk-bound rather then cpu- or memory-bound. So can ...
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0answers
32 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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2answers
627 views

How to use btrfs send/receive for transmitting backup snapshots over a slow and unreliable network connection?

I'd like to use btrfs' send/receive feature for transmitting backup snapshots over a rather slow (initial seed of about 50-100GB, upstream bandwith ~1-2MBit/s) and unreliable (daily forced ...
6
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2answers
516 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 ...
5
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1answer
131 views

Is there any way in BTRFS to set compression permanently?

I have a USB HDD. I want to mount it with compression enabled. I can do in the fstab of my system or even using udev rules. The problem is that I won't mount my USB HDD on my computer only. Up to ...
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22 views

Encrypted file system on external storage [duplicate]

I use archlinux and manjaro. I recently bought an external 2TB toshiba stor.E canvio, and I planned to use it as back up. I used gpt layout and partitioned it with luks and ext4. Dolphin reports 6% ...
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44 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 ...
2
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1answer
340 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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2answers
939 views

Is there a way to monitor progress of a btrfs rebalance?

I'm replacing a failed harddrive in a mirrored btrfs. btrfs device delete missing /[mountpoint] is taking very long, so I assume that it's actually rebalancing data across to the replacement drive. ...
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3answers
372 views

How are filesystem snapshots different from simply making a copy of the files?

by doing this, # btrfs subvolume snapshot /mnt/1 /mnt/1/snapshot # tree /mnt/1 /mnt/1 ├── a ├── snapshot │ ├── a │ └── subv └── subv └── b 3 directories, 3 files We can create snapshot ...
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1answer
230 views

Running du command reports infinity as disk usage

I'm trying to get the total size of what's stored in my home directory. To my surprise, it reports infinity after a few seconds: /home/user $ du -sh . Infinity Huh? I'm pretty sure there are no ...
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124 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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160 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 ...
5
votes
2answers
511 views

Modifying a BTRFS filesystem UUID

I've made backups of my BTRFS filesystem using Clonezilla, and have restored one of those backups to a file named 2013-11-29.sda3.img. I need to get some files out of this backup, but there's a ...
2
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1answer
642 views

Boot partiotionless disk with syslinux

A file system can be configured to span a complete disk, omitting any partition table. Notice intentionally the command to do so does not use /dev/sda1 but the raw, unpartitioned device instead. ...
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1answer
129 views

strange directories on ubuntu 13.10 btrfs partition

I am running Ubuntu 12.04 (ext4) and installed Ubuntu 13.10 on a partition of its own (sda2) with btrfs. I had no time to configure 13.10 to my work environment (yet), so I mounted /dev/sda2 from ...
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0answers
135 views

What's status of btrfs as root fs? [closed]

What is the current status of btrfs being the root filesystem including /boot; meaning that you do not need to create a separate /boot partition. I ask because I noticed on Debian 7 you cannot setup ...
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1answer
85 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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1answer
642 views

How to delete btrfs subvolumes with <FS_TREE> in their name

I have a bunch of btrfs snapshots like so: 20:17:37 [root@galaxy /]$ btrfs subvolume list -a / |grep apt ID 271 gen 348 top level 5 path <FS_TREE>/@apt-snapshot-2013-04-17_21:44:30 ID 272 gen ...
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1answer
300 views

Linux btrfs how to remove unexistent filesystem from list?

I'm giving a try to btrfs. As newbie I did some mistakes, which are good for learning! I created several btrfs filesystems upon different devices (sdX, loop, lvm, etc). During these tests, I removed ...
5
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3answers
654 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 ...
2
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1answer
357 views

btrfs, infamous ENOSPC error while doing a backup from a snapshot

My system is Fedora 19 x86_64 w/3.10.7 kernel. I am trying to use a btrfs snapshot for backing up my /, like this: #!/bin/bash btrfs subvolume snapshot / /snap/ tar -cvf - /snap 2>/dev/null | ...
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309 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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130 views

Does a high “used” value for a device in “btrfs filesystem show” pose a problem? Should a balance operation be performed?

I have a laptop with a Samsung 840 500 GB SSD, and I've installed openSUSE 12.3 with btrfs as the filesystem. A few days ago I first got a message from my web browser about it not being able to save ...
3
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1answer
556 views

Understanding btrfs dmesg

Based on the documentation I found at https://btrfs.wiki.kernel.org/index.php/Data_Structures I am strugeling to understand the following dmesg [ 173.946830] device fsid ...