v0.21 released

v0.21 released

[Sage Weil]

It's been a while, but v0.21 is ready.  Most of the work this time 
around has been on stability. There is one key new feature, however: RBD, 
the rados block device, which let you create a virtual disk backed by 
objects stored in the Ceph cluster.  The images can be mapped natively by 
the ceph kernel module or via a driver in qemu/KVM.  Although neither of 
those drivers is upstream yet, the server side functionality and admin 
tools are in place.

Changes since v0.20 include:

    * improved logging infrastructure
    * log rotate
    * mkfs improvements
    * rbd tool, and rados class
    * mds: return ENOTEMPTY when removing directory with snapshots
    * mds: lazy io support (experimental)
    * msgr: send messages directory to connection handles (more efficient)
    * faster atomic_t via libatomic-ops
    * mon: recovery improvements, fixes (e.g. when one mon is down for a 
long time)
    * mon: warn on monitor clock drift
    * osd: large object support
    * osd: heartbeat improvements, fixes
    * osd: journaling fixes, improvements (bugs, better use of direct io)
    * osd: snapshot rollback op (for rbd)
    * radosgw fixes, improvements
    * many memory leaks and other bugs fixed

The project roadmap has been updated and is available via the issue 
tracker at

	http://tracker.newdream.net/projects/ceph/roadmap

Relevant URLs:

    * Direct download at http://ceph.newdream.net/download/ceph-0.21.tar.gz
    * For Debian packages see http://ceph.newdream.net/wiki/Debian

sage