Hi Guys,
This is my first post to this mailing list so please excuse my ignorance. I started running Alpine Linux Dom0 about half a year ago and I am very happy with it. Recently I inherited a KVM hypervisor with about dozen guests some of which are Windows servers. All KVM guests are either raw or qcow2 image file formats. I am trying to move them from KVM host to Dom0 (not block devices or block device partitions). I did a bit of playing trying to migrate RHEL 7.5 image to Xen Dom0 Alpine. It seems that the only obstacle in importing KVM images into the Xen is the disk naming. Namely KVM is using virtio (paravirtualization driver) for disks which are named as /dev/vda for a OS drive. Xen on the another hand is using different naming convention where the drives inside disk images .img are denoted for example as /dev/xvda When I create DomU out of KVM image file the both process proceed successfully until it drops into dracut shell as it can't find root partition which is on the /dev/vda drive. Is the HDDs naming superficial problem or is it fundamental incompatibility on the level of disk drivers? This is my rhel.cfg file entebuilder = "hvm" name = "rhel75" vcpus=2 memory = 4096 vif = [ 'mac=52:54:00:3b:22:4b, bridge=br0'] disk = [ 'file:/xen-images/rhel75.img,format=raw,xvda,rw' ] boot = "dc" on_reboot="restart" Notice that I did try replacing xvda with vda but it is unrecognized vdev. I also tried putting hda instead which also dropped me to dracut shell during the both process. I am sure I am not the first one who is trying this but except this unhelpful post https://serverfault.com/questions/311709/kvm-to-xen-migration I could not fine any hints about the proper procedure. Best, Predrag _______________________________________________ Xen-users mailing list [hidden email] https://lists.xenproject.org/mailman/listinfo/xen-users |
On Sat, Jun 9, 2018 at 2:06 AM, Predrag Punosevac <[hidden email]> wrote:
> Hi Guys, > > This is my first post to this mailing list so please excuse my > ignorance. I started running Alpine Linux Dom0 about half a year ago and > I am very happy with it. > > Recently I inherited a KVM hypervisor with about dozen guests some of > which are Windows servers. All KVM guests are either raw or qcow2 image > file formats. I am trying to move them from KVM host to Dom0 (not > block devices or block device partitions). > > I did a bit of playing trying to migrate RHEL 7.5 image to Xen Dom0 > Alpine. It seems that the only obstacle in importing KVM images into the > Xen is the disk naming. Namely KVM is using virtio (paravirtualization > driver) for disks which are named as > > /dev/vda > > for a OS drive. Xen on the another hand is using different naming > convention where the drives inside disk images .img are denoted for > example as > > /dev/xvda > > When I create DomU out of KVM image file the both process proceed > successfully until it drops into dracut shell as it can't find root > partition which is on the /dev/vda drive. Is the HDDs naming superficial > problem or is it fundamental incompatibility on the level of disk > drivers? This is my rhel.cfg file It would be helpful to have the actual console output from the guest; look for the 'serial' option in the xl.cfg manpage. But the first thing to check is whether your grub and fstab entries are using persistent device naming[1], or are using hard-coded device names. If your guest grub entry says "root=/dev/vda", then Linux will look for that specific device, not xvda, because that's what you've told it to do; similarly with secondary entries in fstab. If you do have hard-coded device names, the quick-and-dirty option is to go around change vdN to xvdN in grub and fstab. The more robust long-term option is to use UUIDs (or something else); that should be robust against any future device renames as well (for example, if you wanted to try moving back to KVM). -George [1] https://wiki.archlinux.org/index.php/persistent_block_device_naming _______________________________________________ Xen-users mailing list [hidden email] https://lists.xenproject.org/mailman/listinfo/xen-users |
In reply to this post by Predrag Punosevac
Predrag Punosevac schrieb:
> Namely KVM is using virtio (paravirtualization > driver) for disks which are named as > > /dev/vda > > for a OS drive. Xen on the another hand is using different naming > convention where the drives inside disk images .img are denoted for > example as > > /dev/xvda You can also use virtio under Xen! Use the following directive as one line in your xl.cfg (example, please adapt it for your configuration): device_model_args = [ '-drive' , 'file=/path/to/your/root.img,if=virtio,index=0,media=disk,format=raw,cache=writeback' ] -- Manfred Härtel, DB3HM mailto:[hidden email] http://rz-home.de/mhaertel _______________________________________________ Xen-users mailing list [hidden email] https://lists.xenproject.org/mailman/listinfo/xen-users |
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