Is there an OS command I can run from within a Xen based virtual machine to tell me that it is a virtual box rather than a physical box - I heard that the kernel had some self awareness smarts about it. e.g. like an extra column in "ps" output or something? [I know vmstat provides the "st" column but I have seen this on physical host boxes running Linux Kernel 2.6.11 and greater as well].
Many Thanks,
Paul
Dmesg may give some hints from the kernel message buffer, here is output on a virtualized Ubuntu instance from Slicehost:
bvm@qdbp:~$ sudo dmesg | grep Xen
[ 0.000000] Xen: 0000000000000000 - 00000000000a0000 (usable)
[ 0.000000] Xen: 00000000000a0000 - 0000000000100000 (reserved)
[ 0.000000] Xen: 0000000000100000 - 0000000010000000 (usable)
[ 0.000000] Booting paravirtualized kernel on Xen
[ 0.000000] Xen version: 3.1.2-rc1
[ 0.000000] Xen: using vcpu_info placement
[ 0.000000] Xen: using vcpuop timer interface
[ 0.000000] installing Xen timer for CPU 0
[ 0.021223] installing Xen timer for CPU 1
[ 0.046157] installing Xen timer for CPU 2
[ 0.046157] installing Xen timer for CPU 3
[ 0.265880] Initialising Xen virtual ethernet driver.