On 10/10/06, John Cianfarani <[EMAIL PROTECTED]> wrote:
There is a problem with the recent xen 3.0.2+ & kernel and ztdummy. The RTC modules needs access to irq 8 which isn't properly emulated in the domU. No clue if this will be fixed. It's been brought up on the xen-devel list a bunch of times but nobody seems to address the issue. I have been able to get ztdummy to work pretty decent under Xen 3.0.1 (kernel 2.6.12). See results below. Funny enough as long I run the domU with the 2.6.12 kernel I can run Xen 3.0.2 (kernel 2.6.16) on the dom0 without any problems. I don't have any clue what changed for the RTC between 2.6.12 and 2.6.16to remove this functionality. Depending on the type of High Availability you need look into DRBD and Heartbeat. DRBD is like a disk Raid 1 over the network. I'm currently playing with it for some of my own setups. Zttest under a domU --- Results after 287 passes --- Best: 99.987793 -- Worst: 99.975586 -- Average: 99.976386 I've tested this with about 3 domU's running and the timing seems fairly stable. Unless there is a lot of disk activity and then it seems to start to drop. Hope this helps John
<SNIP> John, Thanks for the encouraging info getting ztdummy compiled under xen - I had read of a few other success stories through the miracle of google but with little technical detail. I will have to add your specific kernel suggestions to my list of things to experiment with. Using DRBD is exactly what I had in mind - while I haven't read of anyone using it with xen (because I haven't looked yet), it seems like an excellent fit to provide HA for xen virtual machines. -- sacha
