4:49 a.m.
Hi All,
I have in config of 2 Xen DomU's this disk:
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/dev/mapper/keys'/>
<target dev='xvdz' bus='xen'/>
<readonly/>
</disk>
If I start the DomU's then all starts without problem, see this in log
of the DomU:
{
"pdev_path": "/dev/mapper/keys",
"vdev": "xvdz",
"backend": "qdisk",
"format": "raw",
"removable": 1,
"discard_enable": "False",
"colo_enable": "False",
"colo_restore_enable": "False"
}
but this disk isn't there in the domU... Why?
It is a shared disk between the DomU's but configured as "readonly" so
there shouldnt be a problem (with the same xen xl configuration, there
is no problem)
--
------
Greetz
2:50 p.m.
On 8/27/20 3:49 AM, Christoph wrote:
Hi All,
I have in config of 2 Xen DomU's this disk:
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/dev/mapper/keys'/>
<target dev='xvdz' bus='xen'/>
<readonly/>
</disk>
Using blkback works for me, e.g. <driver name='phy'...>.
If I start the DomU's then all starts without problem, see this
in log
of the DomU:
{
"pdev_path": "/dev/mapper/keys",
"vdev": "xvdz",
"backend": "qdisk",
"format": "raw",
"removable": 1,
"discard_enable": "False",
"colo_enable": "False",
"colo_restore_enable": "False"
}
but this disk isn't there in the domU... Why?
It appears readonly disks only work with blkback.
It is a shared disk between the DomU's but configured as
"readonly" so
there shouldnt be a problem (with the same xen xl configuration, there
is no problem)
What xl config did you use? It doesn't work for me if I specify qdisk and
readonly. E.g. the following does not work
"backendtype=qdisk,format=raw,vdev=xvdz,access=ro,target=..."
Regards,
Jim
3:47 p.m.
Using blkback works for me, e.g. <driver name='phy'...>.
what is the diff to 'qemu'?
What xl config did you use? It doesn't work for me if I specify
qdisk
and readonly. E.g. the following does not work
"backendtype=qdisk,format=raw,vdev=xvdz,access=ro,target=..."
"phy:/dev/mapper/keys,xvdz,r"
Greetz
5:21 p.m.
On 8/27/20 2:47 PM, Christoph wrote:
>
> Using blkback works for me, e.g. <driver name='phy'...>.
>
what is the diff to 'qemu'?
It's just a different block backend. Xen supports both qemu as a block backend
and blkback. blkback only supports raw IIRC. And apparently, when used with Xen,
the qemu backend only support rw.
> What xl config did you use? It doesn't work for me if I
specify qdisk
> and readonly. E.g. the following does not work
>
> "backendtype=qdisk,format=raw,vdev=xvdz,access=ro,target=..."
>
"phy:/dev/mapper/keys,xvdz,r"
As expected you are using blkback.
Regards,
Jim
8:34 p.m.
On 8/27/20 11:53 PM, Christoph wrote:
>>
>> "phy:/dev/mapper/keys,xvdz,r"
>
> As expected you are using blkback.
>
hm then it seems that there is a bug in domxml-from-native virsh
translation... I've done the xml config with: virsh domxml-from-native
xen-xl...
If your disk XML contains <driver name='qemu'/>, which your earlier example
did,
then the conversion is correct since it maps to backendtype=qdisk. If however
your XML contains <driver name='phy'/> and it maps to backendtype=qdisk,
then we
have a bug.
Regards,
Jim
7:33 a.m.
If your disk XML contains <driver name='qemu'/>, which
your earlier
example did, then the conversion is correct since it maps to
backendtype=qdisk. If however your XML contains <driver name='phy'/>
and it maps to backendtype=qdisk, then we have a bug.
my native configuration has:
"phy:/dev/mapper/keys,xvdz,r"
and virsh domxml-from-native ...
has converted ist to <driver name='qemu'/>
so I think this is a bug...
10:15 p.m.
On 9/3/20 6:33 AM, Christoph wrote:
> If your disk XML contains <driver name='qemu'/>,
which your earlier
> example did, then the conversion is correct since it maps to
> backendtype=qdisk. If however your XML contains <driver name='phy'/>
> and it maps to backendtype=qdisk, then we have a bug.
>
my native configuration has:
"phy:/dev/mapper/keys,xvdz,r"
and virsh domxml-from-native ...
has converted ist to <driver name='qemu'/>
so I think this is a bug...
Agreed. Can you also enter an issue in the libvirt gitlab project for this bug?
Alternatively, feel free to open a bug at bugzilla.opensuse.org if you already
have an account.
Regards,
Jim
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