Hey,
Gave me a few ideas for this and I've got a VM from Xen running in my ESXi environment now! It's a juggling act for now, but it's once of so I'll deal with it for now.
For anyone out there, perhaps some of my quick notes might help others too.
My target machine was one of our Radius / DNS load balancer machines. It's running CentOS 5.3 and using the xen kernel. The steps I've taken to get a bootable machine running in ESXi as follows;
- XEN Snapshot the existing machine so all our changes in the VM can be absolutely screwed around with and still have a safety net essentially.
- Modify /etc/modprobe.conf to remove reference to ethX device from "xennet" and the "scsiadapter_xenblk" and added the following lines in;
- alias eth0 e1000
- alias scsi_hostadapter mptbase
- alias scsi_hostadapter1 mptspi
- alias scsi_hostadapter2 ata_piix
- Install the new default kernel --
- Edit the grub configuration and remove all references to the Xen Kernels.
Here I've kicked off my conversion with the standalone converter ( took 3 minutes! ) a few options to change was to ensure that the Ethernet device was set to E1000. Just about everything was configured as normal in this.
Now I've got a machine that wont boot in ESXi. As expected. Booting a CentOS image and chrooting to the system image I've made the following changes to get a bootable system.
- Grub.conf > remove any garbage for xvc0 and I've added the 'noapic' flag in.
- this fixes an issue where init dies booting
- Checkout grub things > "grub-install /dev/sda1/ --recheck" as this will pick up the BIOS changes and boot devices to my understanding. From my question above. The conversion process has changed /dev/xvda to /sda a scsi device and so grub needs to be fixed.
- install grub to the new location > "grub-install /dev/sda1"
- Move the old initrd.img > mv /boot/initrd-xxxx.img initrd--xxxx.img.old
- Build a new initrd image > "mkinitrd /boot/initrd-xxx.img 2.6.18-xxx-el5"
- lots of forums and such with help on rebuilding this. Easy to search for!
- Modify /etc/inittab -- There's a line similar to this "co:2345:respawn:/sbin/agetty xvc0 9600 vt100-nav" that needs to be modified to counter the ld "co" respawn and hangs on boot. Change the it to something such as;
- co:2345:respawn:/sbin/agetty tty1 115200 vt100-nav
Following this, you should now have a booting and working system ( with CentOS 5.3 at least ). Install VMWare Tools and you'll be off!
Ensure you watch the new vm closely for a while and keep an eye on your logs too. My load balancer is working great at the moment, only for about 3 hours now and tested failover to its other node still running on Xen.
Pending all of this, I'll write some better doco and processes and gladly share it here. As anyone reading this will love any assistance going from Xen to ESXi who's never done it before and has limited knowledge of xen virtualisation.
MB.