Am 20.06.2014 12:07, schrieb Marc Joliet: > From my own google search, at least up to 2011 per-subvolume > compression settings were not possible. Then, after subsequently > searching on the btrfs wiki for a while, I finally found an answer: > no. See this FAQ entry: > > https://btrfs.wiki.kernel.org/index.php/FAQ#Can_I_mount_subvolumes_with_different_mount_options.3F > > [...]
This seems to be the same for the option nodatacow. I wanted to test this with VM-images in a separate subvolume, and with this script: https://github.com/stsquad/scripts/blob/master/uncow.py It was mentioned here: https://btrfs.wiki.kernel.org/index.php/FAQ#Can_copy-on-write_be_turned_off_for_data_blocks.3F Does somebody already have experience with turning off COW for specific files like VM images? I would like to take 2 demo VMs with me on my thinkpad, and there I don't have that much flexibility to add another hdd w/ ext4 or something. As far as I have seen so far, for demoing the performance isn't too bad anyway. Stefan
