[CentOS-virt] moving from Xen to KVM

Fri Feb 26 08:03:34 UTC 2010
Christopher G. Stach II <cgs at ldsys.net>

----- "Dave Augustus" <davea at ingraftedsoftware.com> wrote:

> I finally realized that when running Xen and in Dom0, Xen hides the
> AMD-V in /proc/cpuinfo

Really?

dom0:

flags           : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt lm 3dnowext 3dnow constant_tsc pni monitor cx16 lahf_lm cmp_legacy svm cr8_legacy

guest:

flags           : fpu tsc msr pae mce cx8 apic mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt lm 3dnowext 3dnow constant_tsc pni monitor cx16 lahf_lm cmp_legacy svm cr8_legacy

> (...more reasons to move to KVM)

I have a hunch that you are going to do whatever you are told to do and that you really have no idea what is going on.

Can we get more "Hey, I'm told KVM is cool so I'm migrating all of my production servers to it because the free OS of my choice may not support it in a year or two after I leave my current suckjob position and I hear, since I don't read mainline kernel mailing lists religiously and keep only a superficial idea in my head about kernel development, since I really have no idea what 'kernel development' means, that KVM is the only Jesus-approved way of doing things" threads? None of you seem to have have a head for any of this, it seems.

Maybe you're just working for Billy's Interwebs-r-Us and keeping Sally's Nail Shop going strong, but the last time I checked, the "ent" in CentOS stood for "enterprise".

Here are a few tips:

1. Fuck KVM.
2. Stick with Xen because there is quite a lot of time until 5 is EOL'd and if you haven't noticed, it's actually a mature technology.
3. Figure out what you are going to do with Sally's Nail Shop in the meantime. If you have time to fuck everything up in your environment with KVM, you can probably save 20% or more optimizing your environment and even more with proper capital investments and training.
4. Figure out how either a) non-critical/enterprise services would ever be served by KVM's features or lack thereof, or b) you are going to CYA when you can't guarantee an SLA.
5. Spend more time on KVM dev lists instead of posting here and annoying others with your butthurt KVM-won't-work posts, as it's not even supported upstream.

-- 
Christopher G. Stach II
http://ldsys.net/~cgs/