git-annex 0.20110325 released with [[!toggle text="these changes"]]
[[!toggleable text="""
   * Free space checking is now done, for transfers of data for keys
     that have free space metadata. (Notably, not for SHA* keys generated
     with git-annex 0.2x or earlier.) The code is believed to work on
     Linux, FreeBSD, and OSX; check compile-time messages to see if it
     is not enabled for your OS.
   * Add annex.diskreserve config setting, to control how much free space
     to reserve for other purposes and avoid using (defaults to 1 mb).
   * Add --fast flag, that can enable less expensive, but also less thorough
     versions of some commands.
   * fsck: In fast mode, avoid checking checksums.
   * unused: In fast mode, just show all existing temp files as unused,
     and avoid expensive scan for other unused content.
   * migrate: Support migrating v1 SHA keys to v2 SHA keys with
     size information that can be used for free space checking.
   * Fix space leak in fsck and drop commands.
   * migrate: Bugfix for case when migrating a file results in a key that
     is already present in .git/annex/objects.
   * dropunused: Significantly sped up; only read unused log file once."""]]