Hi, Eric
what do you think of this kludged way of
off-line migration?
在 2012-08-02四的 17:02 +0800，liguang写道：
>
> From: liguang <lig.fnst@xxxxxxxxxxxxxx>
>
> a roughly way for offline-migrate (domain defined,
> not started yet), now can do like this:
> migrate --hard-migrate --xml dom.xml dom qemu+ssh://target/system
>
> this patch will push dom.xml and all disk images to target
>
> Signed-off-by: liguang <lig.fnst@xxxxxxxxxxxxxx>
> ---
> tools/virsh.c | 76
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 76 insertions(+), 0 deletions(-)
>
> diff --git a/tools/virsh.c b/tools/virsh.c
> index 53d1825..5793233 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -7344,9 +7344,75 @@ static const vshCmdOptDef opts_migrate[] = {
> {"dname", VSH_OT_DATA, 0, N_("rename to new name during migration
> (if supported)")},
> {"timeout", VSH_OT_INT, 0, N_("force guest to suspend if live
> migration exceeds timeout (in seconds)")},
> {"xml", VSH_OT_STRING, 0, N_("filename containing updated XML for
> the target")},
> + {"hard-migrate", VSH_OT_BOOL, 0, N_("migration when there's no
> domain")},
> {NULL, 0, 0, NULL}
> };
>
> +#define VIR_MIGRATE_HARD 1 << 10
> +#define push_file(file) { \
> + virAsprintf(&topath, "%s:%s", to, file); \
> + cmd = virCommandNewArgList("scp", file, topath, NULL); \
> + vshPrint(ctl, "pushing %s to %s\n", file, to); \
> + if (virCommandRunAsync(cmd, NULL) < 0 || \
> + virCommandWait(cmd, NULL) < 0) { \
> + virshReportError(ctl); \
> + goto cleanup; \
> + } \
> +}
> +
> +static void
> +vshMigrateHard(vshControl *ctl, char *doc, char dst[])
> +{
> + xmlDocPtr xml = NULL;
> + xmlXPathObjectPtr obj= NULL;
> + xmlXPathContextPtr ctxt = NULL;
> + xmlNodePtr *disks = NULL;
> + virCommandPtr cmd;
> + int i = 0, ret = 0;
> + int outfd = STDOUT_FILENO;
> + int errfd = STDERR_FILENO;
> + char *src[] = {NULL}, *to, *topath;
> +
> + if (!vshConnectionUsability(ctl, ctl->conn))
> + return;
> +
> + xml = virXMLParseFileCtxt(doc, &ctxt);
> + if (!xml) {
> + vshError(NULL, "%s", _("Fail to get domain information from"));
> + goto cleanup;
> + }
> +
> + ret = virXPathNodeSet("./devices/disk", ctxt, &disks);
> + if (ret < 0) {
> + vshError(NULL, "%s", _("Fail to get disk node"));
> + goto cleanup;
> + }
> +
> + to = strtok(dst, "/");
> + to = strtok(NULL, "/");
> + virCommandSetInputFD(cmd, STDIN_FILENO);
> + virCommandSetOutputFD(cmd, &outfd);
> + virCommandSetErrorFD(cmd, &errfd);
> +
> + push_file(doc);
> +
> + for (i = 0 ; i < ret ; i++) {
> + ctxt->node = disks[i];
> + src[i] = virXPathString("string(./source/@file"
> + "|./source/@dir"
> + "|./source/@name)", ctxt);
> + push_file(src[i]);
> + }
> +
> +cleanup:
> + xmlXPathFreeObject(obj);
> + xmlXPathFreeContext(ctxt);
> + xmlFreeDoc(xml);
> + virCommandFree(cmd);
> + if (src)
> + VIR_FREE(src); return;
> +}
> +
> static void
> doMigrate (void *opaque)
> {
> @@ -7413,12 +7479,22 @@ doMigrate (void *opaque)
> if (vshCommandOptBool(cmd, "unsafe"))
> flags |= VIR_MIGRATE_UNSAFE;
>
> + if (vshCommandOptBool(cmd, "hard-migrate")) {
> + flags |= VIR_MIGRATE_HARD;
> + if (xmlfile == NULL)
> + vshError(ctl, _("please specify xmlfile for
> hard-migrate"));
> + }
> if (xmlfile &&
> virFileReadAll(xmlfile, 8192, &xml) < 0) {
> vshError(ctl, _("file '%s' doesn't exist"), xmlfile);
> goto out;
> }
>
> + if (flags & VIR_MIGRATE_HARD) {
> + vshMigrateHard(ctl, (char *)xmlfile, (char *)desturi);
> + goto out;
> + }
> +
> if ((flags & VIR_MIGRATE_PEER2PEER) ||
> vshCommandOptBool(cmd, "direct")) {
> /* For peer2peer migration or direct migration we only expect
> one URI
> --
> 1.7.2.5
>
>
> 在 2012-08-01三的 06:13 -0600，Eric Blake写道：
> > On 07/31/2012 09:30 PM, liguang wrote:
> > > Hi, All
> > >
> > > If a VM domain defined, but not started yet,
> > > and I want to migrate it to another server,
> > > so that It can be started at there, what's
> > > should i do? or is it rational?
> >
> > Yes it is rational, and you're not the first to request it.
> > Unfortunately, we haven't yet taught 'virsh migrate' to support offline
> > migration, even though (or because?) it is dead simple to cobble
> > together yourself:
> >
> > source$ virsh dumpxml $dom > file.xml
> > dest$ virsh define file.xml
> >
> > optionally followed by
> > source$ virsh undefine $dom
> >
> > Patches are welcome to make 'virsh migrate' automatically handle an
> > offline migration.
> >
>
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