10:54 a.m.
Any idea what 'virt-customize' script I should use to convert from
virtio-blk (vda, vdb...) to virtio-scsi (sda, sdb...) ?
I've tried naively to convince libvirt to use virtio-scsi and still present
it to the guest as 'vd*' - that didn't work (
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source
file='/dev/shm/run/default/images/lago_basic_suite_master_storage_root.qcow2'/>
<backingStore type='file' index='1'>
<format type='raw'/>
<source file='/home/lagostore/phx_repo:el7-base:latest'/>
<backingStore/>
</backingStore>
* <target dev='vda' bus='scsi'/>*
<boot order='1'/>
<alias name='scsi0-0-0'/>
<address type='drive' controller='0' bus='0'
target='0' unit='0'/>
</disk>
TIA,
Y.
1:03 p.m.
On Thu, Jul 14, 2016 at 06:54:20PM +0300, Yaniv Kaul wrote:
Any idea what 'virt-customize' script I should use to convert
from
virtio-blk (vda, vdb...) to virtio-scsi (sda, sdb...) ?
You'll find that you have to recreate the initrd, else it won't boot
(I'm assuming this is a Linux guest).
This is somewhat complicated and involves running some commands from
the guest. Here's what virt-v2v does, although virt-v2v is especially
complicated because it supports doing this for everything back to RHEL 3(!)
You probably only need to run dracut if you only care about modern
Fedora & RHEL.
https://github.com/libguestfs/libguestfs/blob/master/v2v/convert_linux.ml...
I've tried naively to convince libvirt to use virtio-scsi and
still present
it to the guest as 'vd*' - that didn't work (
Yeah the target dev names in libvirt XML aren't really arbitrary
strings. Device names are controlled by the *guest* kernel, nothing
to do with the host which just exports one or another PCI device.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top
6:29 a.m.
On Thu, Jul 14, 2016 at 9:03 PM, Richard W.M. Jones <rjones(a)redhat.com>
wrote:
On Thu, Jul 14, 2016 at 06:54:20PM +0300, Yaniv Kaul wrote:
> Any idea what 'virt-customize' script I should use to convert from
> virtio-blk (vda, vdb...) to virtio-scsi (sda, sdb...) ?
You'll find that you have to recreate the initrd, else it won't boot
(I'm assuming this is a Linux guest).
This is somewhat complicated and involves running some commands from
the guest. Here's what virt-v2v does, although virt-v2v is especially
complicated because it supports doing this for everything back to RHEL 3(!)
You probably only need to run dracut if you only care about modern
Fedora & RHEL.
https://github.com/libguestfs/libguestfs/blob/master/v2v/convert_linux.ml...
> I've tried naively to convince libvirt to use virtio-scsi and still
present
> it to the guest as 'vd*' - that didn't work (
Yeah the target dev names in libvirt XML aren't really arbitrary
strings. Device names are controlled by the *guest* kernel, nothing
to do with the host which just exports one or another PCI device.
Rich.
Does it make more sense to just use virt-builder and build it from scratch?
I did not find where in virt-builder I can actually specify virtio-scsi as
the type.
(BTW, the reason for all this is mainly to get 'discard' support...)
Y.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top
9:08 a.m.
On Tue, Jul 19, 2016 at 02:29:11PM +0300, Yaniv Kaul wrote:
Does it make more sense to just use virt-builder and build it from
scratch?
I did not find where in virt-builder I can actually specify virtio-scsi as
the type.
virt-builder images should boot on virtio-scsi "out of the box",
certainly the x86-64 ones.
If you like you can check what drivers are supported by the initrd
like this:
$ virt-builder --arch x86_64 fedora-23
$ virt-get-kernel -a fedora-23.img
download: /boot/vmlinuz-4.4.6-300.fc23.x86_64 -> ./vmlinuz-4.4.6-300.fc23.x86_64
download: /boot/initramfs-4.4.6-300.fc23.x86_64.img ->
./initramfs-4.4.6-300.fc23.x86_64.img
$ zcat initramfs-4.4.6-300.fc23.x86_64.img | cpio -it | grep virtio
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/block/virtio_blk.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/char/hw_random/virtio-rng.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/char/virtio_console.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/scsi/virtio_scsi.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/virtio
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/virtio/virtio.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/virtio/virtio_pci.ko.xz
usr/lib/modules/4.4.6-300.fc23.x86_64/kernel/drivers/virtio/virtio_ring.ko.xz
51087 blocks
Hence that particular guest should support booting from virtio-blk or
virtio-scsi.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines. Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top
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