On 26/04/2013 01:42, William Kenworthy wrote: > Does anyone know a good guide to using time sync in VM's, for both > windows and linux (gentoo) guests using libvirt? Especially for guests > that are resumed, or the whole virtualisation system is hibernated? (ntp > refuses to resync after guest pause/save/restore/resume (known problem), > even with "tinker panic 0"
That's not a bug, it's by design. If ntpd detects the clock is out by more than X seconds [1], it will not try to correct the difference, concluding that something is wrong and a human must decide. It can't easily tell the difference between a resumed guest (or even that it was resumed at all) and a severe problem. We fixed this by taking the easy route of least resistance; 1. run ntpdate on startup/restart once before ntpd starts 2. start ntpd as normal 3. a colleague wrote a $MAGIC_HOOK to detect resumed guests that runs ntpdate once True, it's a brutal solution and uses a baseball bat where some finesse might be less ugly, but it suits our needs just fine. [1] I forget what X is and am too lazy to look it up. Is it 30 seconds or thereabouts? -- Alan McKinnon alan.mckin...@gmail.com
