* trivial DNS issues
@ 2008-09-01 9:57 Cristi Magherusan
2008-09-01 10:29 ` [Qemu-devel] " Avi Kivity
0 siblings, 1 reply; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 9:57 UTC (permalink / raw)
To: kvm
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Hello,
It seems that qemu (and our kvm-qemu branch) and virtualbox suffer of
this issue regarding the DNS resolver:
http://www.virtualbox.org/ticket/421
I know it's mostly a DHCP client config problem, but we could try if the
designated DNS servers are reachable before we pass them to our virtual
machine, instead of blindly passing the first one.
Best regards,
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 9:57 trivial DNS issues Cristi Magherusan
@ 2008-09-01 10:29 ` Avi Kivity
0 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 10:29 UTC (permalink / raw)
To: cristi.magherusan; +Cc: kvm, qemu-devel
(copying qemu-devel)
Cristi Magherusan wrote:
> Hello,
>
> It seems that qemu (and our kvm-qemu branch) and virtualbox suffer of
> this issue regarding the DNS resolver:
> http://www.virtualbox.org/ticket/421
>
> I know it's mostly a DHCP client config problem, but we could try if the
> designated DNS servers are reachable before we pass them to our virtual
> machine, instead of blindly passing the first one.
>
What does your /etc/resolv.conf look like?
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 10:29 ` Avi Kivity
0 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 10:29 UTC (permalink / raw)
To: cristi.magherusan; +Cc: qemu-devel, kvm
(copying qemu-devel)
Cristi Magherusan wrote:
> Hello,
>
> It seems that qemu (and our kvm-qemu branch) and virtualbox suffer of
> this issue regarding the DNS resolver:
> http://www.virtualbox.org/ticket/421
>
> I know it's mostly a DHCP client config problem, but we could try if the
> designated DNS servers are reachable before we pass them to our virtual
> machine, instead of blindly passing the first one.
>
What does your /etc/resolv.conf look like?
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 10:29 ` [Qemu-devel] " Avi Kivity
@ 2008-09-01 10:57 ` Cristi Magherusan
-1 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 10:57 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm, qemu-devel
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Hello,
On Mon, 2008-09-01 at 13:29 +0300, Avi Kivity wrote:
> What does your /etc/resolv.conf look like?
It used to look like this:
nameserver 127.0.0.1
nameserver <PRIMARY_DNS_IP>
nameserver <SECONDARY_DNS_IP>
Inside the VM the DNS resolver was broken.
After removing that line from the dhclient config now I have only my
real DNS servers, and DNS works inside the VM.
Those who have installed a local DNS server may need that stuff, but we
can check every entries of resolv.conf and see if we can connect to
their DNS server, and use in our VM the first one that could be reached.
Thanks,
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 10:57 ` Cristi Magherusan
0 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 10:57 UTC (permalink / raw)
To: Avi Kivity; +Cc: qemu-devel, kvm
[-- Attachment #1: Type: text/plain, Size: 778 bytes --]
Hello,
On Mon, 2008-09-01 at 13:29 +0300, Avi Kivity wrote:
> What does your /etc/resolv.conf look like?
It used to look like this:
nameserver 127.0.0.1
nameserver <PRIMARY_DNS_IP>
nameserver <SECONDARY_DNS_IP>
Inside the VM the DNS resolver was broken.
After removing that line from the dhclient config now I have only my
real DNS servers, and DNS works inside the VM.
Those who have installed a local DNS server may need that stuff, but we
can check every entries of resolv.conf and see if we can connect to
their DNS server, and use in our VM the first one that could be reached.
Thanks,
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 10:57 ` [Qemu-devel] " Cristi Magherusan
@ 2008-09-01 11:14 ` Avi Kivity
-1 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 11:14 UTC (permalink / raw)
To: cristi.magherusan; +Cc: kvm, qemu-devel
Cristi Magherusan wrote:
> Those who have installed a local DNS server may need that stuff, but we
> can check every entries of resolv.conf and see if we can connect to
> their DNS server, and use in our VM the first one that could be reached.
>
>
The network maybe down when the VM is started, or the dns server may be
down, or ...
Maybe we should forward the host's dns servers to the guest, replacing
127.0.0.1 by 10.0.2.2.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 11:14 ` Avi Kivity
0 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 11:14 UTC (permalink / raw)
To: cristi.magherusan; +Cc: qemu-devel, kvm
Cristi Magherusan wrote:
> Those who have installed a local DNS server may need that stuff, but we
> can check every entries of resolv.conf and see if we can connect to
> their DNS server, and use in our VM the first one that could be reached.
>
>
The network maybe down when the VM is started, or the dns server may be
down, or ...
Maybe we should forward the host's dns servers to the guest, replacing
127.0.0.1 by 10.0.2.2.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 11:14 ` [Qemu-devel] " Avi Kivity
@ 2008-09-01 12:31 ` Cristi Magherusan
-1 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 12:31 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm, qemu-devel
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On Mon, 2008-09-01 at 14:14 +0300, Avi Kivity wrote:
> Cristi Magherusan wrote:
> > Those who have installed a local DNS server may need that stuff, but we
> > can check every entries of resolv.conf and see if we can connect to
> > their DNS server, and use in our VM the first one that could be reached.
> >
> >
>
> The network maybe down when the VM is started, or the dns server may be
> down, or ...
> Maybe we should forward the host's dns servers to the guest, replacing
> 127.0.0.1 by 10.0.2.2.
Then we should forward them all, but the localhost one should be tested
and skipped if unavailable.
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 12:31 ` Cristi Magherusan
0 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 12:31 UTC (permalink / raw)
To: Avi Kivity; +Cc: qemu-devel, kvm
[-- Attachment #1: Type: text/plain, Size: 787 bytes --]
On Mon, 2008-09-01 at 14:14 +0300, Avi Kivity wrote:
> Cristi Magherusan wrote:
> > Those who have installed a local DNS server may need that stuff, but we
> > can check every entries of resolv.conf and see if we can connect to
> > their DNS server, and use in our VM the first one that could be reached.
> >
> >
>
> The network maybe down when the VM is started, or the dns server may be
> down, or ...
> Maybe we should forward the host's dns servers to the guest, replacing
> 127.0.0.1 by 10.0.2.2.
Then we should forward them all, but the localhost one should be tested
and skipped if unavailable.
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 12:31 ` [Qemu-devel] " Cristi Magherusan
@ 2008-09-01 12:37 ` Avi Kivity
-1 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 12:37 UTC (permalink / raw)
To: cristi.magherusan; +Cc: kvm, qemu-devel
Cristi Magherusan wrote:
> On Mon, 2008-09-01 at 14:14 +0300, Avi Kivity wrote:
>
>> Cristi Magherusan wrote:
>>
>>> Those who have installed a local DNS server may need that stuff, but we
>>> can check every entries of resolv.conf and see if we can connect to
>>> their DNS server, and use in our VM the first one that could be reached.
>>>
>>>
>>>
>> The network maybe down when the VM is started, or the dns server may be
>> down, or ...
>> Maybe we should forward the host's dns servers to the guest, replacing
>> 127.0.0.1 by 10.0.2.2.
>>
> Then we should forward them all, but the localhost one should be tested
> and skipped if unavailable.
>
Why? A local application will have exactly the same problems with a
broken dns server on localhost, as a virtual machine with that address
forwarded. And if the the dns server is later fixed, both the local
application and the guest will recover.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 12:37 ` Avi Kivity
0 siblings, 0 replies; 13+ messages in thread
From: Avi Kivity @ 2008-09-01 12:37 UTC (permalink / raw)
To: cristi.magherusan; +Cc: qemu-devel, kvm
Cristi Magherusan wrote:
> On Mon, 2008-09-01 at 14:14 +0300, Avi Kivity wrote:
>
>> Cristi Magherusan wrote:
>>
>>> Those who have installed a local DNS server may need that stuff, but we
>>> can check every entries of resolv.conf and see if we can connect to
>>> their DNS server, and use in our VM the first one that could be reached.
>>>
>>>
>>>
>> The network maybe down when the VM is started, or the dns server may be
>> down, or ...
>> Maybe we should forward the host's dns servers to the guest, replacing
>> 127.0.0.1 by 10.0.2.2.
>>
> Then we should forward them all, but the localhost one should be tested
> and skipped if unavailable.
>
Why? A local application will have exactly the same problems with a
broken dns server on localhost, as a virtual machine with that address
forwarded. And if the the dns server is later fixed, both the local
application and the guest will recover.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: trivial DNS issues
2008-09-01 12:37 ` [Qemu-devel] " Avi Kivity
@ 2008-09-01 14:35 ` Cristi Magherusan
-1 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 14:35 UTC (permalink / raw)
To: Avi Kivity; +Cc: kvm, qemu-devel
[-- Attachment #1: Type: text/plain, Size: 642 bytes --]
On Mon, 2008-09-01 at 15:37 +0300, Avi Kivity wrote:
> Why? A local application will have exactly the same problems with a
> broken dns server on localhost, as a virtual machine with that address
> forwarded. And if the the dns server is later fixed, both the local
> application and the guest will recover.
Okay, then maybe we should just pass them all to the VM and replace
localhost's address, if present, with the internal gateway just like you
said before.
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
* [Qemu-devel] Re: trivial DNS issues
@ 2008-09-01 14:35 ` Cristi Magherusan
0 siblings, 0 replies; 13+ messages in thread
From: Cristi Magherusan @ 2008-09-01 14:35 UTC (permalink / raw)
To: Avi Kivity; +Cc: qemu-devel, kvm
[-- Attachment #1: Type: text/plain, Size: 642 bytes --]
On Mon, 2008-09-01 at 15:37 +0300, Avi Kivity wrote:
> Why? A local application will have exactly the same problems with a
> broken dns server on localhost, as a virtual machine with that address
> forwarded. And if the the dns server is later fixed, both the local
> application and the guest will recover.
Okay, then maybe we should just pass them all to the VM and replace
localhost's address, if present, with the internal gateway just like you
said before.
Cristi
--
Ing. Cristi Măgherușan,
Universitatea Tehnică din Cluj-Napoca
Centrul de Comunicații "Pusztai Kalman"
Tel. 0264/401247 http://cc.utcluj.ro
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^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2008-09-01 14:35 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-09-01 9:57 trivial DNS issues Cristi Magherusan
2008-09-01 10:29 ` Avi Kivity
2008-09-01 10:29 ` [Qemu-devel] " Avi Kivity
2008-09-01 10:57 ` Cristi Magherusan
2008-09-01 10:57 ` [Qemu-devel] " Cristi Magherusan
2008-09-01 11:14 ` Avi Kivity
2008-09-01 11:14 ` [Qemu-devel] " Avi Kivity
2008-09-01 12:31 ` Cristi Magherusan
2008-09-01 12:31 ` [Qemu-devel] " Cristi Magherusan
2008-09-01 12:37 ` Avi Kivity
2008-09-01 12:37 ` [Qemu-devel] " Avi Kivity
2008-09-01 14:35 ` Cristi Magherusan
2008-09-01 14:35 ` [Qemu-devel] " Cristi Magherusan
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