Zumastor Linux Storage Project
Zumastor is Free software that adds enterprise storage features (primarily improved snapshots and remote replication) to Linux.
You can read all about it in the Zumastor Howto.
The current release is 0.8, which adds
several bugfixes (in particular, replication between x86 and x86_64 hosts now works)
and experimental native Hardy packages.
Prebuilt Debian/Ubuntu packages are available at zumastor.org/downloads/releases.
Zumastor development is hosted at zumastor.googlecode.com.
Zumastor requires a few kernel patches. These are online at
The most interesting patches are:
- Dan Phillips' bio throttling patch,
part of how we prevent deadlock during memory pressure. See
lkml discussion from 6 Dec 2007 and
coverage at LWN.NET.
- Dan Phillips' PR_SET_MEMALLOC/PR_SET_LESS_THROTTLE patch, other part of how we prevent deadlock during memory pressure. (Any user app that's in the block writeout path needs to be written very carefully to avoid memory recursion deadlock; in particular, it should probably use mlockall, never allocate any memory while handling a write request (modulo a few KB of Heisenslop), and it should set PF_LESS_THROTTLE|PF_MEMALLOC using prctl, as provided for by this patch.) (Mixed in with the ddsnap stuff for now, sorry; ignore everything but the changes to include/linux/prctl.h and kernel/sys.c.)
- NFS suspend patch, part of how we make new snapshots available via the NFS server as they arrive from remote sites
Daniel Phillips, Jiaying Zhang, Shapor Naghibzadeh, Drake Diedrich, Will Nowak, Timothy Huber
- Robert Nelson, Jane Chiu, Ross Combs, Alex Polvi, Chuan-kai Lin, Mark Roach
- Phil Dibowitz - ddsnap SIGHUP handling patch
- Jonathan Van Eenwyk - ddloop deltafile mount patch (tarball includes a paper)
© 2007, 2008 Google