On 09/18/2009 03:09 AM, Charles Duffy wrote:
Daniel P. Berrange wrote:
> Hmm, bad error message :-( We might also need todo a chown()
> in the restore path to allow QEMU to read it. NB there is no
> compatability between QEMU version, so if you have upgraded
> your install of QEMU between the time you saved & restored
> it is very likely to crash & burn.
How difficult would it be to set up named pipes for save and restore
operations, and splice from those pipes to the actual files on the
libvirtd side? Seems much preferable from a security perspective to
chown'ing things around, and (unlike pipes set up ahead of time with
pipe() and friends) shouldn't be disrupted by a libvirtd restart.
For a recent enough QEMU, you could also use the
migrate-to-file-descriptor functionality which uses SCM_RIGHTS. It is
in QEMU 0.12 only, but since the plumbing is in 0.11 too we could ask
for a backport.
Paolo