> But to the contrary. I tested live-migrate (without block migrate) > last night using a guest with 8GB RAM (almost fully committed) and > lost any access/contact with the guest for over 4 minutes - it was > paused for the duration. Not something I'd want to do to a user's > web-server on a regular basis...
4 minutes of pause (down time)? That's way too long. Even there was crazy memory intensive workload inside the VM being migrated, the worst case is KVM has to pause VM and transmit all 8 GB memory (all memory are dirty, which is very rare). If you have 1GbE link between two host, that worst case pause period (down time) is less than 2 minutes. My previous experience is: the down time for migrating one idle (almost no memory access) 8GB VM via 1GbE is less than 1 second; the down time for migrating a 8 GB VM that page got dirty really quickly is <60 seconds. FYI. -- Regards Huang Zhiteng _______________________________________________ Mailing list: https://launchpad.net/~openstack Post to : openstack@lists.launchpad.net Unsubscribe : https://launchpad.net/~openstack More help : https://help.launchpad.net/ListHelp