[Qemu-devel] VM Memory limit with kernel-kqemu?

[Qemu-devel] VM Memory limit with kernel-kqemu?

[Andrew Barr]

I'm running a Windows 2000 SP4 guest on a Linux 2.6.16 host with Qemu CVS and 
kqemu 1.3.0pre3. I am trying to use -kernel-kqemu. I have been allocating 256 
MB of RAM to my guest (out of 768 MB total) and I have found that using that 
amount of memory with -kernel-kqemu causes Windows 2000 to freeze at the 
graphical boot up screen (after 'Starting Windows...') and qemu to take up 
95-100% CPU. Reducing the amount of guest RAM to 160 MB makes that problem go 
away. I also tried 192 MB and that did not work. Is there a limit to the 
amount of memory that may be used with the -kernel-kqemu option?

-- 
Andrew Barr			| 1024D/AD9AE76A
andrew.james.barr@gmail.com	| http://www.oakcourt.dyndns.org/~andrew

And now for something completely different.

Re: [Qemu-devel] VM Memory limit with kernel-kqemu?

[Kevin F. Quinn]

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On Sun, 26 Mar 2006 14:48:11 -0500
Andrew Barr <andrew.james.barr@gmail.com> wrote:

> I'm running a Windows 2000 SP4 guest on a Linux 2.6.16 host with Qemu
> CVS and kqemu 1.3.0pre3. I am trying to use -kernel-kqemu. I have
> been allocating 256 MB of RAM to my guest (out of 768 MB total) and I
> have found that using that amount of memory with -kernel-kqemu causes
> Windows 2000 to freeze at the graphical boot up screen (after
> 'Starting Windows...') and qemu to take up 95-100% CPU. Reducing the
> amount of guest RAM to 160 MB makes that problem go away. I also
> tried 192 MB and that did not work. Is there a limit to the amount of
> memory that may be used with the -kernel-kqemu option?

I found the same when I tried 256M - it works with 384M (with which
qemu uses about half of my 1GB) so I didn't look into it further.

-- 
Kevin F. Quinn

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Re: [Qemu-devel] VM Memory limit with kernel-kqemu?

[Brad Campbell]

Andrew Barr wrote:
> I'm running a Windows 2000 SP4 guest on a Linux 2.6.16 host with Qemu CVS and 
> kqemu 1.3.0pre3. I am trying to use -kernel-kqemu. I have been allocating 256 
> MB of RAM to my guest (out of 768 MB total) and I have found that using that 
> amount of memory with -kernel-kqemu causes Windows 2000 to freeze at the 
> graphical boot up screen (after 'Starting Windows...') and qemu to take up 
> 95-100% CPU. Reducing the amount of guest RAM to 160 MB makes that problem go 
> away. I also tried 192 MB and that did not work. Is there a limit to the 
> amount of memory that may be used with the -kernel-kqemu option?
> 

I've used it with 512M with no problems.. how big is your tmpfs on the host?

I found a while ago (prior to -kernel-kqemu) nasty things happened if you tried to allocate more 
memory than you had space available in /tmp

I have mine configured for 1.5GB (I have 3GB of ram) and I can run 3 concurrent sessions, 2 with 
512MB and 1 with 256MB and no problems. (All win2k sp4 guests)

Filesystem            Size  Used Avail Use% Mounted on
192.168.2.82:/nfsroot
                       165G   68G   89G  44% /
tmpfs                 1.5G  4.0K  1.5G   1% /dev/shm
none                  1.5G  1.2M  1.5G   1% /tmp
tmpfs                  10M  2.7M  7.4M  27% /dev

Regards,
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VM Memory limit with kernel-kqemu?

[Brad Campbell]

--RESEND-- Can someone let me know if this comes through twice? I'm having huge problems getting 
through to the list it would appear.

Andrew Barr wrote:
> I'm running a Windows 2000 SP4 guest on a Linux 2.6.16 host with Qemu CVS and 
> kqemu 1.3.0pre3. I am trying to use -kernel-kqemu. I have been allocating 256 
> MB of RAM to my guest (out of 768 MB total) and I have found that using that 
> amount of memory with -kernel-kqemu causes Windows 2000 to freeze at the 
> graphical boot up screen (after 'Starting Windows...') and qemu to take up 
> 95-100% CPU. Reducing the amount of guest RAM to 160 MB makes that problem go 
> away. I also tried 192 MB and that did not work. Is there a limit to the 
> amount of memory that may be used with the -kernel-kqemu option?
> 

I've used it with 512M with no problems.. how big is your tmpfs on the host?

I found a while ago (prior to -kernel-kqemu) nasty things happened if you tried to allocate more
memory than you had space available in /tmp

I have mine configured for 1.5GB (I have 3GB of ram) and I can run 3 concurrent sessions, 2 with
512MB and 1 with 256MB and no problems. (All win2k sp4 guests)

Filesystem            Size  Used Avail Use% Mounted on
192.168.2.82:/nfsroot
                       165G   68G   89G  44% /
tmpfs                 1.5G  4.0K  1.5G   1% /dev/shm
none                  1.5G  1.2M  1.5G   1% /tmp
tmpfs                  10M  2.7M  7.4M  27% /dev

Regards,
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VM Memory limit with kernel-kqemu?

[Brad Campbell]

Andrew Barr wrote:
> I'm running a Windows 2000 SP4 guest on a Linux 2.6.16 host with Qemu CVS and 
> kqemu 1.3.0pre3. I am trying to use -kernel-kqemu. I have been allocating 256 
> MB of RAM to my guest (out of 768 MB total) and I have found that using that 
> amount of memory with -kernel-kqemu causes Windows 2000 to freeze at the 
> graphical boot up screen (after 'Starting Windows...') and qemu to take up 
> 95-100% CPU. Reducing the amount of guest RAM to 160 MB makes that problem go 
> away. I also tried 192 MB and that did not work. Is there a limit to the 
> amount of memory that may be used with the -kernel-kqemu option?
> 

Ok I've just reproduced this with the 256M problem.... doing some more homework.

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams