From 84cdb5b95b921725f369b5b0a5588a606aab96cc Mon Sep 17 00:00:00 2001 From: Evan Broder Date: Fri, 31 Oct 2008 14:00:19 -0400 Subject: [PATCH 1/1] Add some additional documentation on how the sysvm disk locking works svn path=/trunk/packages/invirt-xen-config/; revision=1462 --- debian/invirt-xen-config.init | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/debian/invirt-xen-config.init b/debian/invirt-xen-config.init index 02dedc1..ec23d0d 100755 --- a/debian/invirt-xen-config.init +++ b/debian/invirt-xen-config.init @@ -39,7 +39,11 @@ start_sysvm() { fi if lvchange -a n "$DISK" >/dev/null 2>&1 && lvchange -a ey "$DISK" >/dev/null 2>&1; then - # If we can lock on the VM's disk, then the VM isn't running + # If we can disable and then re-enable the VMs disk, then the + # VM can't be running. If the lvchange -a ey succeeds, then we + # have an exclusive lock across the cluster on enabling the + # disk, which avoids the potential race condition of two hosts + # starting a VM at the same time [ "$VERBOSE" != no ] && log_daemon_msg "Starting sysvm $VM" xm create "sysvms/$VM" >/dev/null [ "$VERBOSE" != no ] && log_end_msg $? -- 1.7.9.5