-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 1/7/2013 4:27 AM, Sankar P wrote: > Hi, > > Is there any technical article explaining how defragmentation works > in linux filesystems, say btrfs or ext4 ? > > Do they recreate the file data blocks and change the root pointer > to the new extent ? Or do they do some kind of moving blocks around > ? Or is it based on some other strategy ? Partial defragmentation > (based on either byte offset or extents) is also supported by any > of the file systems ? e4defrag uses an ioctl to allocate a new donor inode with enough contiguous blocks to hold the original, then atomically copy the blocks and swap the pointers. > Is there a standard way to trigger a defragmentation operation (an > ioctl ?) that my filesystem could implement so that any user space > tool that work with other fs will work with mine too ? (Like, how > FIEBMAP ioctl can help in giving the extent information for a file > from the userspace) No. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJQ9cjmAAoJEJrBOlT6nu754ZkH/2ZGsCpKMDQoZN8/82scAlXl DYZK/4ckttnxB5EiXSygBnGqdjAdR7IK+q+JJxUok7uLAAgGux1yKq4NX6pyd0f9 MIbMGYNHy1Mwn9uel+eGxPcvFF1s4p38tknZp1ZqBFbWpcnhJN5mTgBHHm+SLuLG d7GsFMBHiHr0IyMW8gWxiLEs4jDXSU1N8lDAcxOZCinE+A5DAUtWTPx3moTk6JYU u69pPQr/A5Krp1eLCIQCIPw4JkM1yWoX9Tfs2SL88okWxP+OD1JXfoOfKmzbUdLd bs0wJSkyK/VddK1YJbXGEi0zH2c4ue3DyYu4Kc9JizxL8vQk+XJUJAJI9vexR58= =G3lC -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
