it always create sdx device when I configure ide device with hdx name

[marshell]

I have configured 2 ide disks with name starting with hd, but when the vm boots up, it shows disks whose name starting with sd.

1. ide disks in vm xml:

    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/data3_raw.qcow2'/>
      <target dev='hdc' bus='ide'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/data2.qcow2'/>
      <target dev='hdb' bus='ide'/>
    </disk>

2. in VM:

sda 8:0 0 2G 0 disk
sdb 8:16 0 1G 0 disk

3. from vm.log:

le=/data2.qcow2,format=qcow2,if=none,id=drive-ide0-0-1 -device ide-hd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -drive file=/data3_raw.qcow2,format=raw,if=none,id=drive-ide0-1-0 -device ide-hd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -netdev t

4. rpm info: (I got the same issue on 2 diff envs)
(1) env1
qemu-kvm-1.5.3-105
libvirt-3.2.0-14.el7
(2) env2
libvirt-5.9.0-1.el8
qemu-4.1.0-1.el8

[Eric Blake (eblake)]

On 6/6/20 5:50 AM, marshell wrote:
> Public bug reported:
>
> I have configured 2 ide disks with name starting with hd, but when the
> vm boots up, it shows disks whose name starting with sd.

This looks more like a libvirt question than a qemu one.

>
> 1. ide disks in vm xml:
>
> <disk type='file' device='disk'>
> <driver name='qemu' type='raw'/>
> <source file='/data3_raw.qcow2'/>
> <target dev='hdc' bus='ide'/>
> </disk>
> <disk type='file' device='disk'>
> <driver name='qemu' type='qcow2'/>
> <source file='/data2.qcow2'/>
> <target dev='hdb' bus='ide'/>
> </disk>

The name that libvirt chooses to identify disks from the host
perspective is independent...

>
>
> 2. in VM:
>
> sda 8:0 0 2G 0 disk
> sdb 8:16 0 1G 0 disk

...from what the guest OS chooses to use. Although there are many
situations where a Linux guest will pick the same names as libvirt chose
on the host side based on the transport (such as SCSI or virtio), there
is no guarantee that this is always the case, nor that your guest is
always running Linux as its OS.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc. [phone]
Virtualization: qemu.org | libvirt.org

[marshell (winndows)]

Thanks a lot for the reply.

But from the cmdline of qemu, we can see as following, libvirt passed "-device" option with "ide-hd, bus=ide.0" to qemu. I am wondering why qemu received this option, but it is still dealing it as scsi bus device instead of ide bus device, since with "lssci" cmd, we can see the ide disk we configured in xml.

>3. from vm.log:

>le=/data2.qcow2,format=qcow2,if=none,id=drive-ide0-0-1 -device ide-hd,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 >-drive file=/data3_raw.qcow2,format=raw,if=none,id=drive-ide0-1-0 -device ide-hd,bus=ide.1,unit=0,drive=drive-ide0-1->0,id=ide0-1-0 -netdev t

[Thomas Huth (th-huth)]

Which kernel / linux distro are you using in the guest? Can you spot something related in the output of "dmesg" in the guest?

[Launchpad Janitor (janitor)]

[Expired for QEMU because there has been no activity for 60 days.]