* Free memory reported but not used in new domain creation?
@ 2013-08-12 5:46 G.R.
2013-08-12 6:15 ` Pasi Kärkkäinen
0 siblings, 1 reply; 5+ messages in thread
From: G.R. @ 2013-08-12 5:46 UTC (permalink / raw)
To: xen-devel
Hi guys,
I need your help understanding this behavior:
My host has 8GB RAM installed. Xen reports about 1.8G free memory with
three domains running.
xl info|grep memory
total_memory : 7887
free_memory : 1833
xl list
Name ID Mem VCPUs State Time(s)
Domain-0 0 768 8 r----- 650.2
nas 1 3072 2 -b---- 704.0
windom 3 2047 4 r----- 520.7
Now, when I tried to launch a forth domain with 1G memory assigned,
here is the result:
xl list
Name ID Mem VCPUs State Time(s)
Domain-0 0 380 8 r----- 654.1
nas 1 3072 2 -b---- 706.7
windom 3 2047 4 r----- 529.8
freebsd 5 1024 1 -b---- 0.7
xl info|grep memory
total_memory : 7887
free_memory : 1184
As you can see, hypervisor is ballooning memory from dom0 instead of
allocating from free_memory. If I increase the guest memory of the new
domain to 1.5G or 2G. It simply fails to launch, saying something like
dom0 memory is below minimal threshold.
This gives me the impression that the free_memory is fake. Is it an
expected behavior?
What are the remaining 1GB memory for?
PS: I'm on the xen 4.3.0 release.
Thanks,
Timothy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Free memory reported but not used in new domain creation?
2013-08-12 5:46 Free memory reported but not used in new domain creation? G.R.
@ 2013-08-12 6:15 ` Pasi Kärkkäinen
2013-08-12 7:55 ` G.R.
0 siblings, 1 reply; 5+ messages in thread
From: Pasi Kärkkäinen @ 2013-08-12 6:15 UTC (permalink / raw)
To: G.R.; +Cc: xen-devel
On Mon, Aug 12, 2013 at 01:46:30PM +0800, G.R. wrote:
> Hi guys,
> I need your help understanding this behavior:
>
> My host has 8GB RAM installed. Xen reports about 1.8G free memory with
> three domains running.
>
> xl info|grep memory
> total_memory : 7887
> free_memory : 1833
>
> xl list
> Name ID Mem VCPUs State Time(s)
> Domain-0 0 768 8 r----- 650.2
> nas 1 3072 2 -b---- 704.0
> windom 3 2047 4 r----- 520.7
>
> Now, when I tried to launch a forth domain with 1G memory assigned,
> here is the result:
>
> xl list
> Name ID Mem VCPUs State Time(s)
> Domain-0 0 380 8 r----- 654.1
> nas 1 3072 2 -b---- 706.7
> windom 3 2047 4 r----- 529.8
> freebsd 5 1024 1 -b---- 0.7
>
> xl info|grep memory
> total_memory : 7887
> free_memory : 1184
>
> As you can see, hypervisor is ballooning memory from dom0 instead of
> allocating from free_memory. If I increase the guest memory of the new
> domain to 1.5G or 2G. It simply fails to launch, saying something like
> dom0 memory is below minimal threshold.
>
> This gives me the impression that the free_memory is fake. Is it an
> expected behavior?
> What are the remaining 1GB memory for?
>
> PS: I'm on the xen 4.3.0 release.
>
Hello,
This is a long-standing bug in xl.
The workaround is to disable xl autoballooning..
http://wiki.xen.org/wiki/Xen_Best_Practices
-- Pasi
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Free memory reported but not used in new domain creation?
2013-08-12 6:15 ` Pasi Kärkkäinen
@ 2013-08-12 7:55 ` G.R.
2013-08-12 8:02 ` Pasi Kärkkäinen
2013-08-12 12:53 ` Konrad Rzeszutek Wilk
0 siblings, 2 replies; 5+ messages in thread
From: G.R. @ 2013-08-12 7:55 UTC (permalink / raw)
To: Pasi Kärkkäinen; +Cc: xen-devel
On Mon, Aug 12, 2013 at 2:15 PM, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> On Mon, Aug 12, 2013 at 01:46:30PM +0800, G.R. wrote:
>> Hi guys,
>> I need your help understanding this behavior:
>>
>> My host has 8GB RAM installed. Xen reports about 1.8G free memory with
>> three domains running.
>>
>> xl info|grep memory
>> total_memory : 7887
>> free_memory : 1833
>>
>> xl list
>> Name ID Mem VCPUs State Time(s)
>> Domain-0 0 768 8 r----- 650.2
>> nas 1 3072 2 -b---- 704.0
>> windom 3 2047 4 r----- 520.7
>>
>> Now, when I tried to launch a forth domain with 1G memory assigned,
>> here is the result:
>>
>> xl list
>> Name ID Mem VCPUs State Time(s)
>> Domain-0 0 380 8 r----- 654.1
>> nas 1 3072 2 -b---- 706.7
>> windom 3 2047 4 r----- 529.8
>> freebsd 5 1024 1 -b---- 0.7
>>
>> xl info|grep memory
>> total_memory : 7887
>> free_memory : 1184
>>
>> As you can see, hypervisor is ballooning memory from dom0 instead of
>> allocating from free_memory. If I increase the guest memory of the new
>> domain to 1.5G or 2G. It simply fails to launch, saying something like
>> dom0 memory is below minimal threshold.
>>
>> This gives me the impression that the free_memory is fake. Is it an
>> expected behavior?
>> What are the remaining 1GB memory for?
>>
>> PS: I'm on the xen 4.3.0 release.
>>
>
> Hello,
>
> This is a long-standing bug in xl.
> The workaround is to disable xl autoballooning..
>
> http://wiki.xen.org/wiki/Xen_Best_Practices
>
Thanks for the info. It'll be great if you can point me to the bug /
thread for reference.
I thought I was following that page, but maybe I made some mistake and
the config does not take effect:
xen_commandline : placeholder
dom0_mem=1G,max:1536M,min:768M,dom0_max_vcpus=6,vpmu=1
If there are any syntax error, shouldn't it raise error?
> -- Pasi
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Free memory reported but not used in new domain creation?
2013-08-12 7:55 ` G.R.
@ 2013-08-12 8:02 ` Pasi Kärkkäinen
2013-08-12 12:53 ` Konrad Rzeszutek Wilk
1 sibling, 0 replies; 5+ messages in thread
From: Pasi Kärkkäinen @ 2013-08-12 8:02 UTC (permalink / raw)
To: G.R.; +Cc: xen-devel
On Mon, Aug 12, 2013 at 03:55:17PM +0800, G.R. wrote:
> On Mon, Aug 12, 2013 at 2:15 PM, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> > On Mon, Aug 12, 2013 at 01:46:30PM +0800, G.R. wrote:
> >> Hi guys,
> >> I need your help understanding this behavior:
> >>
> >> My host has 8GB RAM installed. Xen reports about 1.8G free memory with
> >> three domains running.
> >>
> >> xl info|grep memory
> >> total_memory : 7887
> >> free_memory : 1833
> >>
> >> xl list
> >> Name ID Mem VCPUs State Time(s)
> >> Domain-0 0 768 8 r----- 650.2
> >> nas 1 3072 2 -b---- 704.0
> >> windom 3 2047 4 r----- 520.7
> >>
> >> Now, when I tried to launch a forth domain with 1G memory assigned,
> >> here is the result:
> >>
> >> xl list
> >> Name ID Mem VCPUs State Time(s)
> >> Domain-0 0 380 8 r----- 654.1
> >> nas 1 3072 2 -b---- 706.7
> >> windom 3 2047 4 r----- 529.8
> >> freebsd 5 1024 1 -b---- 0.7
> >>
> >> xl info|grep memory
> >> total_memory : 7887
> >> free_memory : 1184
> >>
> >> As you can see, hypervisor is ballooning memory from dom0 instead of
> >> allocating from free_memory. If I increase the guest memory of the new
> >> domain to 1.5G or 2G. It simply fails to launch, saying something like
> >> dom0 memory is below minimal threshold.
> >>
> >> This gives me the impression that the free_memory is fake. Is it an
> >> expected behavior?
> >> What are the remaining 1GB memory for?
> >>
> >> PS: I'm on the xen 4.3.0 release.
> >>
> >
> > Hello,
> >
> > This is a long-standing bug in xl.
> > The workaround is to disable xl autoballooning..
> >
> > http://wiki.xen.org/wiki/Xen_Best_Practices
> >
>
> Thanks for the info. It'll be great if you can point me to the bug /
> thread for reference.
>
I don't think there's a "bug entry" about it,
but it has been discussed multiple times here on xen-devel,
and multiple people have reported the issue..
So far the response has mainly been "disable autoballoon".
But I think it'd be better if it worked out-of-the-box!
> I thought I was following that page, but maybe I made some mistake and
> the config does not take effect:
>
> xen_commandline : placeholder
> dom0_mem=1G,max:1536M,min:768M,dom0_max_vcpus=6,vpmu=1
>
> If there are any syntax error, shouldn't it raise error?
>
So you need to set autoballoon=0 in /etc/xen/xl.conf
-- Pasi
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Free memory reported but not used in new domain creation?
2013-08-12 7:55 ` G.R.
2013-08-12 8:02 ` Pasi Kärkkäinen
@ 2013-08-12 12:53 ` Konrad Rzeszutek Wilk
1 sibling, 0 replies; 5+ messages in thread
From: Konrad Rzeszutek Wilk @ 2013-08-12 12:53 UTC (permalink / raw)
To: G.R.; +Cc: xen-devel
On Mon, Aug 12, 2013 at 03:55:17PM +0800, G.R. wrote:
> On Mon, Aug 12, 2013 at 2:15 PM, Pasi Kärkkäinen <pasik@iki.fi> wrote:
> > On Mon, Aug 12, 2013 at 01:46:30PM +0800, G.R. wrote:
> >> Hi guys,
> >> I need your help understanding this behavior:
> >>
> >> My host has 8GB RAM installed. Xen reports about 1.8G free memory with
> >> three domains running.
> >>
> >> xl info|grep memory
> >> total_memory : 7887
> >> free_memory : 1833
> >>
> >> xl list
> >> Name ID Mem VCPUs State Time(s)
> >> Domain-0 0 768 8 r----- 650.2
> >> nas 1 3072 2 -b---- 704.0
> >> windom 3 2047 4 r----- 520.7
> >>
> >> Now, when I tried to launch a forth domain with 1G memory assigned,
> >> here is the result:
> >>
> >> xl list
> >> Name ID Mem VCPUs State Time(s)
> >> Domain-0 0 380 8 r----- 654.1
> >> nas 1 3072 2 -b---- 706.7
> >> windom 3 2047 4 r----- 529.8
> >> freebsd 5 1024 1 -b---- 0.7
> >>
> >> xl info|grep memory
> >> total_memory : 7887
> >> free_memory : 1184
> >>
> >> As you can see, hypervisor is ballooning memory from dom0 instead of
> >> allocating from free_memory. If I increase the guest memory of the new
> >> domain to 1.5G or 2G. It simply fails to launch, saying something like
> >> dom0 memory is below minimal threshold.
> >>
> >> This gives me the impression that the free_memory is fake. Is it an
> >> expected behavior?
> >> What are the remaining 1GB memory for?
> >>
> >> PS: I'm on the xen 4.3.0 release.
> >>
> >
> > Hello,
> >
> > This is a long-standing bug in xl.
> > The workaround is to disable xl autoballooning..
> >
> > http://wiki.xen.org/wiki/Xen_Best_Practices
> >
>
> Thanks for the info. It'll be great if you can point me to the bug /
> thread for reference.
>
> I thought I was following that page, but maybe I made some mistake and
> the config does not take effect:
>
> xen_commandline : placeholder
> dom0_mem=1G,max:1536M,min:768M,dom0_max_vcpus=6,vpmu=1
You need to use spaces instead of ','.
>
> If there are any syntax error, shouldn't it raise error?
>
> > -- Pasi
> >
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-08-12 12:53 UTC | newest]
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2013-08-12 5:46 Free memory reported but not used in new domain creation? G.R.
2013-08-12 6:15 ` Pasi Kärkkäinen
2013-08-12 7:55 ` G.R.
2013-08-12 8:02 ` Pasi Kärkkäinen
2013-08-12 12:53 ` Konrad Rzeszutek Wilk
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