A volume-managing, snapshot-supporting copy-on-write (COW) filesystem included in the Linux kernel.
Questions tagged [btrfs]
790 questions
61
votes
6 answers
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 shells?
Fabian Henze
- 713
- 1
- 5
- 7
52
votes
1 answer
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) writable, somehow.
But neither the btrfs subvolume…
derobert
- 107,579
- 20
- 231
- 279
33
votes
9 answers
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 git, LVM or btrfs snapshots or a backup program for…
taffer
- 1,553
- 11
- 19
31
votes
7 answers
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 can I get rid of this?
cnvzmxcvmcx
- 527
- 1
- 4
- 9
26
votes
3 answers
Practical 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 be in addition to my current off site backup…
StrongBad
- 5,151
- 9
- 47
- 73
25
votes
3 answers
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.
Issuing a simple rm on a typical file system…
loopbackbee
- 4,442
- 3
- 24
- 30
25
votes
1 answer
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 understanding, let alone a solution.
The question in…
schlimmchen
- 1,307
- 2
- 12
- 16
24
votes
2 answers
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?
imz -- Ivan Zakharyaschev
- 15,113
- 15
- 61
- 123
24
votes
2 answers
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 hitch. Since the backup is of this machine, I cannot…
Naftuli Kay
- 38,686
- 85
- 220
- 311
23
votes
3 answers
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)?
jl6
- 1,415
- 2
- 13
- 29
23
votes
4 answers
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%
The following page indicates that I should run the…
MountainX
- 17,168
- 59
- 155
- 264
22
votes
3 answers
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 distributions (From Wikipedia: openSUSE 11.3, SLES 11…
user7136
21
votes
5 answers
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.
Is there any way to monitor the progress of such an…
user50849
- 5,082
- 5
- 25
- 30
20
votes
2 answers
Move a Linux installation 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 new snapshots or subvolumes to be created inside the root filesystem, which is quite…
loopbackbee
- 4,442
- 3
- 24
- 30
20
votes
2 answers
What ext4 functionality does btrfs not support?
btrfs (often pronounced "better fs") has quite a few features that ext4 lacks.
However, comparing the functionality of btrfs vs ext4, what is lacking in btrfs?1
In other words, what can I do with ext4 that I can't with btrfs?
1 Ignoring the lesser…
Tom Hale
- 28,728
- 32
- 139
- 229