On Wed, Apr 21, 2010 at 03:03:43PM -0600, Eric Blake wrote:
On 04/21/2010 10:56 AM, Daniel P. Berrange wrote:
The save process was relying on use of the shell >> append operator to ensure the save data was placed after the libvirt header + XML. This doesn't work for block devices though. Replace this code with use of 'dd' and its 'seek' parameter.
The qemuMonitorMigateToCommand() monitor API is used for both save/coredump, and migration via UNIX socket. We can't simply switch this to use 'dd' since this causes problems with the migration usage. Thus, create a dedicated qemuMonitorMigateToFile which can accept an filename + offset, and remove the filename from the current qemuMonitorMigateToCommand() API
+++ b/src/qemu/qemu_driver.c @@ -4789,6 +4789,7 @@ static int qemudDomainSaveFlag(virDomainPtr dom, const char *path, qemuDomainObjPrivatePtr priv; struct stat sb; int is_bdev = 0; + unsigned long long offset;
Should this be off_t instead of ull?
@@ -1673,7 +1701,8 @@ int qemuMonitorJSONMigrateToCommand(qemuMonitorPtr mon, goto cleanup; }
- if (virAsprintf(&dest, "exec:%s >>%s 2>/dev/null", argstr, safe_target) < 0) { + if (virAsprintf(&dest, "exec:%s | dd of=%s seek=%llub", + argstr, safe_target, offset) < 0) {
Don't you still need to silence stderr, particularly since dd writes to stderr even on success? (2 instances)
I didn't want to silence stderr, because I want it to end up in the QEMU logfile if anything goes wrong. So i really need a way to make dd keep quiet on success, rather than throwing away stderr Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|