Data loss on btrfs!!
So it finally happened. I've seen 0 byte files turn up here and there, the odd image which can't be opened where I was almost sure it used to be fine.
So what happened? chmod -R on a directory and the directory went from 28gb to 1.5gb! Now I have a lot of 0 byte files in there which were not 0 byte files just seconds before, so I am sure it was chmod which is responsible, guessing in part with it being a btrfs file system.
Is chmod not to be used on a btrfs filesystem? I haven't read much documentation and have made up for my ignorance by keeping 2+ backups of everything, so I'm doing fine at the moment. I read something about btrfs working great, until it doesn't. Meaning it is so functional and robust (and fault tolerant!) is seems like there isn't anything wrong with it. Except people do run into problems with it. I'm thinking of turning a couple of my backup drives into ext4 or jfs. That way it won't all be btrfs.