Re: [libvirt] [PATCH] Compressed save image format for Qemu.

On Thu, Aug 13, 2009 at 10:47:18AM +0200, Chris Lalancette wrote: > Implement a compressed save image format for qemu. While ideally > we would have the choice between compressed/non-compressed > available to the libvirt API, unfortunately there is no "flags" > parameter to the virDomainSave() API. Therefore, implement this > as a qemu.conf option. Both gzip and bzip2 are implemented, and > it should be very easy to implement additional compression > methods. > > One open question is if/how we should detect the gzip and bzip2 > binaries. One way to do it is to do compile-time setting of the > paths (via configure.in), but that doesn't seem like a great thing > to do. Another solution (my preferred solution) is not to detect > at all; when we go to run the commands that need them, if they > aren't available, or aren't available in one of the standard paths, > then we'll fail. Maybe somebody else has another option or > opinion, though. > > In the future, we'll have a more robust (managed) save/restore API, > at which time we can expose this functionality properly in the API. > > V2: get rid of redundant dd command and just use >> to append data. > V3: Add back the missing pieces for the enum and bumping the save version. > V4: Make the compressed field in the save_header an int. > Implement LZMA compression. > > Signed-off-by: Chris Lalancette <clalance(a)redhat.com&gt; ACK, this looks good now. Bonus points if you do a follow-up patch to add the new param to libvirtd_qemu.aug and test_libvirtd_qemu.aug.

> /* Set the migration source and start it up. */ > ret = qemudStartVMDaemon(conn, driver, vm, "stdio", fd); > + if (intermediate_pid != -1) { > + /* Wait for intermediate process to exit */ > + while (waitpid(intermediate_pid, &childstat, 0) == -1 && > + errno == EINTR); > + } > + if (intermediatefd != -1) > + close(intermediatefd); > close(fd); > fd = -1; > if (ret < 0) { Oh actually need a VIR_FREE(driver->save_image_format) in qemudShutdown()