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

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21
votes
9answers
2k views

How to keep track of changes in /etc/

I would like to keep track of changes in /etc/ Basically I'd like to know if a file was changed, by yum update or by a user and roll it back if I don't like the chage. I thought of using a VCS like ...
14
votes
3answers
1k views

Securely delete files on btrfs filesystem

Sometimes, there's the need to delete a file in a filesystem, and make sure that the file is truly gone. A file that contains sensitive passwords, for example, should be throughly wiped from the disk. ...
13
votes
3answers
3k views

What are the advantages of Btrfs for end users?

Btrfs has begun to gain some momentum in replacing ext4 as the default filesystem of choice for a few distributions such as Fedora Core 16. It is experimentally available in a number of other ...
12
votes
5answers
2k views

Is btrfs stable enough for home usage? [closed]

btrfs has finally found its way into the latest kernels, is it considered stable and safe enough to use in a home backup scenario (as an alternative to zfs) ?
8
votes
2answers
851 views

What keeps one side of an rsync so busy?

I've got a Debian machine on my LAN serving as a backup server for the others. It has four HDDs combined into a software RAID 5 md device, on that an LVM, and on that btrfs. Backups are made using ...
8
votes
2answers
2k views

How to create a snapshot in btrfs, and then rollback to it after some work?

What are the commands to use in btrfs in case I want to: create a (read-only) snapshot of a volume; (do some experiments in the volume); and then rollback the volume to the snapshot?
7
votes
2answers
735 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 ...
7
votes
3answers
778 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 ...
6
votes
1answer
1k views

Are there any deduplication scripts that use btrfs CoW as dedup?

Looking for deduplication tools on Linux there are plenty, see e.g. this wiki page. Allmost all scripts do either only detection, printing the duplicate file names or removing duplicate files by ...
6
votes
1answer
926 views

Move a linux instalation using btrfs on the default subvolume (subvolid=0) to another subvolume

When doing a installation to a root btrfs filesystem, many linux distributions install to the default subvolume. If left unmodified, this layout will force any snapshots or subvolumes to be created ...
6
votes
3answers
2k views

How to create a read-only snapshot in btrfs?

As far as I understand, the snapshots made by btrfs subvolume snapshot are writable by default and are visible at a certain path under the mountpoint of your btrfs volume. How to setup the system so ...
6
votes
0answers
32 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 ...
5
votes
2answers
270 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
votes
2answers
1k views

How to clone btrfs filesystem into different medium preserving snapshots' sharing data

I have decided to give btrfs raid capabilities a try. I set up a btrfs with sudo mkfs.btrfs -m raid10 -d raid10 /dev/sda9 /dev/sdb9 /dev/sdc9 /dev/sdd9 Now I want to clone my existing btrfs ...
5
votes
3answers
3k 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 ...
5
votes
1answer
227 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 ...
5
votes
2answers
371 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 ...
5
votes
1answer
577 views

btrfs and the discard mount option on an ssd

I can't seem to find an answer to this so I thought I would ask here: In /etc/fstab and when using the mount command in ext4 you would add the option discard to activate TRIM on an SSD. Similarly ...
5
votes
1answer
84 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 ...
4
votes
2answers
5k 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, ...
4
votes
1answer
2k views

When using btrfs, why “Size”, “Used” and “Avail” values from df do not match?

I have a btrfs partition. When I run df -h, it shows: Filesystem Size Used Avail Use% Mounted on /dev/sda2 113G 101G 8.3G 93% /home From Why is that? Is it because reserved space for ...
4
votes
2answers
652 views

btrfs on openSUSE not releasing disk space

I have an openSUSE 12.1 install on my main desktop running with btrfs filesystem for root (/boot is ext4). I started having issues today with KDE informing me that disk space is almost all gone and ...
3
votes
1answer
2k views

Why does btrfs allow to create a raid1 with mismatched drives?

I'm creating a btrfs using sudo mkfs.btrfs -m raid1 -d raid1 <small-disk> <large-disk> or sudo mkfs.btrfs -m raid1 -d raid1 <large-disk> <small-disk> it creates the fs with ...
3
votes
3answers
501 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 ...
3
votes
1answer
168 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 ...
3
votes
1answer
181 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 ...
3
votes
1answer
5k views

How do I fix btrfs? [closed]

I've trawled mailing lists and finally finished up on Ubuntu's btrfs page, and am left feeling that btrfs still does not have a full fixing utility (as indicated on their home page). Even though ...
3
votes
1answer
36 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 ...
3
votes
1answer
237 views

Online remount btrfs of root filesystem with different subvolume (snapshot)

Let's say you have a btrfs root filesystem on an online system. You want to revert the filesystem to an earlier state, of which you have a snapshot: remount /dev/sdaX / -o remount,subvol=snapshots/Y ...
3
votes
0answers
141 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 ...
3
votes
1answer
438 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 ...
3
votes
0answers
260 views

btrfs change after system upgrade broke apt-btrfs-snapshot

After upgrading (via apt-get dist-upgrade) a Mint 14 Linux box to Mint 15, apt-btrfs-snapshot seems to have stopped working: 18:25:48 [root@galaxy ~]$ apt-btrfs-snapshot list Sorry, your system lacks ...
3
votes
0answers
348 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 ...
3
votes
0answers
132 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 ...
2
votes
1answer
326 views

Will using a compressed filesystem over an encrypted volume improve performance?

Encryption/decryption is often the main bottleneck when accessing an encrypted volume. Would using a filesystem with a fast transparent compression (such as BTRFS + LZO) help? The idea is that there ...
2
votes
2answers
58 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 ...
2
votes
1answer
691 views

Graphical Btrfs tool

Is there a graphical tool for creating Btrfs sub-partitions and in particular, subpartitions like "GParted" or "system-config-lvm"? I'm running Debian squeeze. In response to the first comment, Btrfs ...
2
votes
2answers
1k 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 ...
2
votes
1answer
68 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 ...
2
votes
1answer
400 views

Can btrfs handle different RAID levels for different subvolumes?

I'd like to assign different RAID levels to different subvolumes in my btrfs filesystem, eg have a subvolume /home that uses RAID 1 and a subvolume /var that uses RAID 0. Is that at all possible (if ...
2
votes
3answers
347 views

Uncopyable 5GB file, BTRFS

I have a 5.3GB tar file, located on a BTRFS partitioned eSATA drive. When trying to copy the file to another disk, or expand the tar the process seems to freeze. No errors are generated, and waiting ...
2
votes
1answer
446 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. ...
2
votes
1answer
153 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 ...
2
votes
1answer
308 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 | ...
2
votes
1answer
239 views

Incomplete factory update makes btrfs filesystem unusable?

After an incomplete update from the factory repo my opensuse 12.1 btrfs filesystem is unusable. I have plenty of disk space free but zero inodes. When I try to delete or create a file it gives me the ...
2
votes
1answer
218 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 ...
2
votes
0answers
124 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 ...
2
votes
1answer
396 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 ...
2
votes
0answers
273 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 ...
1
vote
2answers
513 views

btrfs performance

I decided to mess around with btrfs and found some weird performance anomalies. The tests I've done are with with two external hard drives one formatted with ext4 the other btrfs. ext4 performance ...