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VM Snapshots Code Released

By April 21, 2009March 4th, 2019Announcements

Patrick Colp at the recent Xen Summit at Oracle described his project and has announced the release of the source code. From his email:
I’ve been working on VM snapshots/CoW for Xen (as seen at Xen Summit this year). I’m happy to release my first version.
There are some known issues with capturing page dirties for HVM guests. I think it’s related to the QEMU code (I believe I’m not catching the pages that QEMU dirties). However, it works with both 32-bit and 64-bit PV guests.
This release includes modifications to Linux, Xen, and some tools (a
library, FUSE fs, and testing tool).
The FUSE file system will take a snapshot if you try to create a file in
the directory you mount the xencowfs file system too.
The testing tool pauses a domain, enables CoW, takes a dump of the CoW image, takes two live memory dumps, unpauses the domain for a bit, then takes another CoW image. It compares all the images and reports on which pages are different.
These patches are against xen-unstable revision 19425, however I had no trouble patching them against the current revision of xen-unstable (19553).
Please remember this is an alpha release, so there is likely to be some
problems. Please let me know if you find any!