Re: [Bug 1882350] [NEW] it always create sdx device when I configure ide device with hdx name

[Eric Blake]

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.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org