What is the actual state of brtfs? - Bombthecat
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zinkalu
Used it since 2011? I think, on various laptops. Used snapshotting frequently,
and RAID1. No stability issues at all.

(I've had some very minor issues with ext3 in the past, massive corruption
caused by LVM, lots of empty files with XFS, etc. btrfs did much better than
any of these in the stability department.)

Performance has improved recently. Apparently, laptop SSDs can cause massive
pauses when a sync is done? It used to be that the whole system froze for a
long time; with kernel 4.8 and newer versions of btrfs, it seems that the
pauses caused by SSDs does not have as severe an effect as they previously
did.

Using it over a network (NBD) has been stable, but with a large number of
files or blocks (not sure which) in the filesystem, it all of a sudden gets
extremely slow. Something I would like to see improved (here's to hoping...).

Storing virtual machines on it works very poorly. Say that you install
KVM+QEMU on a host system, format the harddrives with btrfs, disable COW with
chattr, create a virtual hard disk (in RAW mode, no QCOW), then install an OS
and enable LUKS and btrfs on top of that in the virtual machine. This, for
some reason, causes _massive_ fragmentation of the virtual machine hard drive
file. It's something like a 4 TB disk would have 4 billion fragments, every
single time. Multiply by a number of virtual machines, and you will quickly
get tired of pausing virtual machines, copying the entire virtual harddrive
from one file to another in the host system to get rid of the fragmentation,
and un-pausing the virtual machines. A very big issue, so don't do this.. Not
sure what the best filesystem (apart from VMFS) is for storing virtual
harddrive images...

~~~
osandov
I'm curious about your NBD performance issues. When you say large number of
blocks, are you talking a large filesystem? The free space cache tends to be a
performance bottleneck for large filesystems, you might want to try out
space_cache=v2.

------
svjatoslav
I'm using it without data loss incidents for over 1.5 years now. On SSD drive
I have encrypted volume. On top of it I have LVM volume. Ot top of it BTRFS
partition. I use compress-force=lzo,autodefrag mount options. Works well for
personal computer use case. I always follow latest kernel from Debian
backports repo. I red that some RAID modes are implemented poorly it BTRFS
still.

~~~
Someone
[https://wiki.archlinux.org/index.php/Btrfs#RAID](https://wiki.archlinux.org/index.php/Btrfs#RAID):
_" Parity RAID (RAID 5/6) code has multiple serious data-loss bugs in it."_.

AFAIK, that was true back in July. It likely still is.

I have no opinion on whether using it without it is safe, but I would
definitely avoid RAID.

~~~
bantunes
A fix has been proposed recently:

[http://www.spinics.net/lists/linux-
btrfs/msg60595.html](http://www.spinics.net/lists/linux-btrfs/msg60595.html)

~~~
Bombthecat
Ha thanks! That what I was hoping for!

