On 10/27/14, 7:41 AM, "Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote:
>It should be possible to postcopy block storage as well, if that's >the question (it might take some work to make sure that they play >nicely together; e.g. wanting to making the page transfer higher >priority than block transfer). >However, I thought there were other ways to do block storage >migration (using blockcopy I think? but I'm not a block guy). Honestly (and frankly), it is a complete *ahem* ³challenge² to walk into a project that is in a state of high flux and attempt to ascertain the terminology in use with little usable documentation. I am trying to learn, however. I believe I understand the above statement, but there¹s a more fundamental issue for which I can find no discussion anywhere on the inter web. So perhaps it would be sensible if I explain my context. Here¹s the problem: a (working) peer-to-peer transfer of a modest VM succeeds (PEER2PEER, PERSIST_DEST, NON_SHARED_INC) (running under libvirt), regardless of its size. As soon as the TUNNELLED [sic] flag is added (because security is a good thing) the transfer of the qcow2 file completes but the sending side throws an error. The migration therefore fails with an ³unexpected error² according to libvirt logging. A smaller (about 1.9 GB) VM succeeds,ostensibly because it completes before some timeout value is reached. My conclusion is that the timeout throws an invalid error, and based upon patch 47, my conclusion seems reasonable. I¹d like to: 1) understand if/when the patches that went by on 10/3 (47 pieces?) are going to be committed, and if so, how do I access them? A git clone today didn¹t include that code, and I¹d like to test that modification to see if it addresses my failure. 2) I¹d also love to understand how to turn on tracing in what becomes the qemu-system_x86_64 executable on Ubuntu 14.04. Command line options are valueless when I don¹t control the invocation of the process. Thus I wonder if there is a config file mechanism or environment variable that can be used? That presumes, of course, that I¹ve managed to even build the system with tracing enabledŠ. Searching wiki.qemu.org has been so far fruitless. The word ³trace² shows up in exactly one document, in the discussion of command line parameters. I need to crawl into the engine to find and resolve this failure; at this point the challenge is getting the hood open. Any advice/pointers from any corner would be greatly appreciated.
