Hello friends! On Mon, Oct 2, 2017 at 3:03 PM, Tanstaafl <[email protected]> wrote: > On 10/2/2017, 2:39:51 PM, Stroller <[email protected]> wrote: >> >>> On 2 Oct 2017, at 18:30, Tanstaafl <[email protected]> wrote: >>> >>> One thing I do seem to recall is there was somewhere that I had to >>> define Xen as the virtualization environment being used, but I can't >>> remember where I did that. Was that in the kernel config? If so, their >>> tool should (hopefully) handle that change. >> >> See last lines: >> >> ~ $ grep -B 25 -ie xen -ie kvm /etc/rc.conf > <snip> >> # "xen0" - Xen0 Domain (Linux and NetBSD) >> # "xenU" - XenU Domain (Linux and NetBSD) >> ~ $ >> >> This on a Linode host, BTW. They haven't told me I need to do anything, so I >> hope I'm ok. >> >> HTH, > > Thanks! Yes, at least now I know where that was specified... and since > there is nothing there for kvm, I guess you just leave it commented, BUT... > > yours doesn't appear to be set?? Mine is set to "xenU". >
Due to the nature of how both Xen and QEMU/KVM work, there is no need to set any kernel configuration that tells the kernel it is running on virtual hardware. However, if you do so, you will see performance gains. Some of these performance gains are visible outside of the virtualized system so hosting providers would be within their rights to require specific configuration, but I expect they would have made it obvious. Refer to https://wiki.gentoo.org/wiki/QEMU/Linux_guest, but these settings require support from Linode. > So... maybe I've never even needed this? Or maybe I did way back when I > first installed this (probably 7 or 8 years ago), and it isn't needed > any longer? Would the need for it be based on the kernel version? OR the > underlying Xen Host version? Or something else? > > More importantly - I guess I should comment it out right before the > migration? Or is this something I can do after? IF I don't, how would I > handle it? > As long as your kernel has the appropriate drivers (i.e. you didn't include only the virtualized Xen drivers and left most of the default options intact) it should boot under QEMU/KVM or even on a bare metal system. Cheers, R0b0t1
