[libvirt] on special migration(domain defined, not started yet)
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? seems libvirt migration process haven't consider this condition, e.g. virsh migrate --p2p --tunnelled dom1 qemu+ssh://1.1.1.1/system will fail @ qemuMigrationPerformJob where it call virDomainObjIsActive to see if domain is active, but now domain is inactive, so fail. Thanks!
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. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
From: liguang <lig.fnst@cn.fujitsu.com> 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@cn.fujitsu.com> --- 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.
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@cn.fujitsu.com>
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@cn.fujitsu.com> --- 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.
On 08/07/2012 02:00 AM, liguang wrote:
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@cn.fujitsu.com>
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
Having virsh be able to do this makes it possible to port to older libvirtd, but I'd really like to first see support for offline migration directly in the virDomainMigrate* APIs.
Signed-off-by: liguang <lig.fnst@cn.fujitsu.com> --- 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")},
I'd rather see a name like --offline.
{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) { \
If you're just going to wait for a file, then virCommandRun() is better than virCommandRunAsync/virCommandWait.
+ virshReportError(ctl); \ + goto cleanup; \ + } \ +} + +static void +vshMigrateHard(vshControl *ctl, char *doc, char dst[])
const char *, if this function isn't going to alter 'doc' or '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, "/");
strtok() is not thread-safe, and may not be used in libvirt sources. Run 'make syntax-check' to flag things like this.
+ 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]);
Using scp to copy disk images does not seem like the right approach - it doesn't scale to non-ssh connections. Rather, we should be using libvirt API, like virStorageVolUpload().
+ } + +cleanup: + xmlXPathFreeObject(obj); + xmlXPathFreeContext(ctxt); + xmlFreeDoc(xml); + virCommandFree(cmd); + if (src) + VIR_FREE(src); return;
Formatting is off.
+} + 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 you aren't calling the libvirt API, then don't stick a random bit in the 'flags' parameter destined for that API. Instead, use a new bool variable to track whether the user is requesting offline migration.
+ 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 --
-- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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