So, is there such a method: in a specified directory, the compression feature is enabled, and the file in this directory will be compressed automatically, while the others don't enable compression. thanks. 2010/7/29 Wang Shaoyan <stufever@xxxxxxxxx>: > A prerequisite is: when first mounted file system, not specify '-o > compress' options, only on mount subvolume > Below is my test: > # mkfs.btrfs /dev/sda8 > # mount /dev/sda8 btrfs > # df > Used: 56k > # btrfs subvolume create mysubvolume > # mkdir some_dir_in_root > # mount -o compress,subvol=mysubvolume /dev/sda8 some_dir_in_root > # cd some_dir_in_root > # dd if=/dev/zero of=bigfile count=2048 //create a all-0 file of 1M byte > # df > Used:1088k > we can find it is not compressed at all. > > Another test:if we mount subvolume with "-o compress" first, then we > mount /dev/sda8 without "-o compress", and create a test file in > somewhere not in subvolume, we can find the file is compressed too. > > 2010/7/29 Miao Xie <miaox@xxxxxxxxxxxxxx>: >> On Thu, 29 Jul 2010 15:50:28 +0800, Wang Shaoyan wrote: >>> >>> Hi. >>> I want a subvolume in root to be compressed, I try to do this: >>> # mkfs.btrfs /dev/sda8 >>> # mount /dev/sda8 /home/usr/btrfs >>> # cd /home/usr/btrfs >>> # btrfs subvolume create mysubvolume >>> # mount -o compress,subvol=mysubvolume /dev/sda8 some_dir_in_root >>> but when I create a file in some_dir_in_root, the file isn't >>> compressed at all. why? How can I specify some subvolumes to be >>> compressed, and the others Not to be compressed in a single btrfs? >> >> The method that you said is right, by this way, I can create a compressed >> file >> on the specified subvolume. >> >> I think your file has been compressed or is hard to be compressed, so >> you found it isn't compressed at all. Just like we use a zip tool to >> compress >> a compressed file, we will find the file isn't compressed at all. >> >> Thanks >> Miao >> >>> >>> -- >>> Wang Shaoyan >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >> >> > > > > -- > Wang Shaoyan > -- Wang Shaoyan -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
