On 05/11/2012 01:07 PM, Regendoerp, Achim wrote: >> -----Original Message----- >> From: centos-boun...@centos.org [mailto:centos-boun...@centos.org] On >> Behalf Of Theo Band >> Sent: 11 May 2012 11:51 >> To: CentOS mailing list >> Subject: [CentOS] How to prevent virtual machines running twice on the disk >> images? >> >> I use KVM on two identical centos5 hosts. >> >> I can live migrate the virtual machines from one to the other and it works >> great. Once I do this, I can see VM definitions on both hosts using virt- >> manager or virsh list --all On one machine the VM is running, on the other it >> reports "shut off". >> The disk images are accessible to both host machines and I want to have only >> one running a the time (of course). If the VM locks up, I could by mistake >> think that the machine is not running and try to start it on the wrong host. >> >> My question is, how can I prevent host A from starting a "shut off" VM that >> actually has been migrated to host B? The VM could actually be running on >> any another host. It could also have been crashed. The most simple solution >> would be some sort of lock file placed next to the disk image location, so >> seen by all hosts. But perhaps there is another way of working with virt- >> manager that I am not aware of? >> >> Theo > Are those machines clustered? I used drbd/pacemaker/corosync to achieve > something similar across two CentOS hosts with KVM machines, and the VM can > only be started on the master node where the DRBD drive is mounted and > accessible. Live migrations are fairly easy too with this method > No, not clustered. drbd I do use, but that means a drbd block devices for every individual vm. I tried that but find it a lot of effort to maintain. One shared (NFS) filesystem gives a lot more freedom to move a VM to a machine host machine that has a lower load. I don't mind doing that by hand. It's not for high availability.
Theo _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
