Re: 3525MB RAM Limit
I was thinking of a bug when using large pages, which may not be your problem. There have been other reports recently, with workarounds, that are similar, just not the exact same number you have. some subjects to look for: * Can't boot guest with more than 3585MB when using large pages There was a patch from Marcelo that was supposed to fix it. * kvm-84 and guests with more than 3536 MB Ram? there were suggestions to make sure to use the correct bios and the OP stated that upgrading his kernel actually fixed the problem I could swear there was another one, but maybe I'm thinking of the IRC channel. If you are still unable to get it to work, you should reply back with more info. Kernel version, KVM version, etc. Good luck. --Brian Jackson On Thursday 09 April 2009 10:07:36 Daniel Scott wrote: Hi, Thanks for the response. I have read through the archives (I also did so before posting :) ) but I haven't been able to find any information about this. Do you know where I can find it? I tried searching for 4GB and 3525MB and various combinations. Do you know if a specific limit is mentioned? Thanks, Dan 2009/4/6 Brian Jackson i...@theiggy.com: Read the list archives. A fix was discussed recently. --Brian Jackson On Monday 06 April 2009 21:59:24 Daniel Scott wrote: Hi, I'm running a KVM host using Fedora 10 (x86_64) on 4x Quad-Core AMD Opteron(tm) Processor 8347 HE system with 16GB ram. I've created a Fedora 10 (x86_64) guest and allocated 8 CPUs and 8GB ram which I can see using 'virt-manager'. When I login to the guest, I can see the 8 CPUs, but apparently, I only have 3525MB RAM (output from 'free'). At first I thought it was a 32bit problem, but I've double checked and the host and guest are both running 64bit architectures. virt-manager shows 50% ram usage which appears to be correct (4GB, out of 8). It also correctly recognises the 16GB available in the host machine. Is this expected? Will the extra ram become available once it is required? If not, does anyone have any Ideas for how I can fix the problem? Thanks, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [kvm] Re: 3525MB RAM Limit
On Thu, 2009-04-09 at 10:39 -0500, Brian Jackson wrote: I was thinking of a bug when using large pages, which may not be your problem. There have been other reports recently, with workarounds, that are similar, just not the exact same number you have. some subjects to look for: * Can't boot guest with more than 3585MB when using large pages There was a patch from Marcelo that was supposed to fix it. * kvm-84 and guests with more than 3536 MB Ram? there were suggestions to make sure to use the correct bios and the OP stated that upgrading his kernel actually fixed the problem I could swear there was another one, but maybe I'm thinking of the IRC channel. If you are still unable to get it to work, you should reply back with more info. Kernel version, KVM version, etc. It could also be related to the guest trimming away memory due to the way we used to report the MTRRs. This would show up in dmesg on the guest. Try the latest kvm by hand and see if the problem goes away. Thanks, Alex -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: 3525MB RAM Limit
Thanks Brian, The kvm host with the problem is running: * Fedora release 10 (Cambridge) * kernel: 2.6.27 (the actual fedora package is 2.6.27.21-170.2.56.fc10.x86_64) * 4x Quad-Core AMD Opteron(tm) Processor 8347 HE * KVM version: 74 (the actual fedora package is (kvm-74-10.fc10.x86_64) Reading some other post in forums, it seems kvm should be able to handle 4gb ram. Is this correct? Best, Mauro On Thu, Apr 9, 2009 at 11:49 AM, Daniel Scott djsc...@mit.edu wrote: -- Forwarded message -- From: Brian Jackson i...@theiggy.com Date: 2009/4/9 Subject: Re: 3525MB RAM Limit To: Daniel Scott djsc...@mit.edu Cc: kvm@vger.kernel.org I was thinking of a bug when using large pages, which may not be your problem. There have been other reports recently, with workarounds, that are similar, just not the exact same number you have. some subjects to look for: * Can't boot guest with more than 3585MB when using large pages There was a patch from Marcelo that was supposed to fix it. * kvm-84 and guests with more than 3536 MB Ram? there were suggestions to make sure to use the correct bios and the OP stated that upgrading his kernel actually fixed the problem I could swear there was another one, but maybe I'm thinking of the IRC channel. If you are still unable to get it to work, you should reply back with more info. Kernel version, KVM version, etc. Good luck. --Brian Jackson -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: 3525MB RAM Limit
Hi, Thanks for the response. I have read through the archives (I also did so before posting :) ) but I haven't been able to find any information about this. Do you know where I can find it? I tried searching for 4GB and 3525MB and various combinations. Do you know if a specific limit is mentioned? Thanks, Dan 2009/4/6 Brian Jackson i...@theiggy.com: Read the list archives. A fix was discussed recently. --Brian Jackson On Monday 06 April 2009 21:59:24 Daniel Scott wrote: Hi, I'm running a KVM host using Fedora 10 (x86_64) on 4x Quad-Core AMD Opteron(tm) Processor 8347 HE system with 16GB ram. I've created a Fedora 10 (x86_64) guest and allocated 8 CPUs and 8GB ram which I can see using 'virt-manager'. When I login to the guest, I can see the 8 CPUs, but apparently, I only have 3525MB RAM (output from 'free'). At first I thought it was a 32bit problem, but I've double checked and the host and guest are both running 64bit architectures. virt-manager shows 50% ram usage which appears to be correct (4GB, out of 8). It also correctly recognises the 16GB available in the host machine. Is this expected? Will the extra ram become available once it is required? If not, does anyone have any Ideas for how I can fix the problem? Thanks, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [kvm] Re: 3525MB RAM Limit
Brian, Alex, 2009/4/9 Alex Williamson alex.william...@hp.com: On Thu, 2009-04-09 at 10:39 -0500, Brian Jackson wrote: some subjects to look for: * Can't boot guest with more than 3585MB when using large pages There was a patch from Marcelo that was supposed to fix it. * kvm-84 and guests with more than 3536 MB Ram? there were suggestions to make sure to use the correct bios and the OP stated that upgrading his kernel actually fixed the problem I could swear there was another one, but maybe I'm thinking of the IRC channel. If you are still unable to get it to work, you should reply back with more info. Kernel version, KVM version, etc. It could also be related to the guest trimming away memory due to the way we used to report the MTRRs. This would show up in dmesg on the guest. Try the latest kvm by hand and see if the problem goes away. Thanks for the suggestions. After more research, it looks like upgrading the software will fix the problem: http://www.func.nl/community/knowledgebase/running-kvm-guest-35-gb-ram We see the same BIOS message as in the above link. It seems like this will be fixed in Fedora 11 so we'll probably wait for a month or two and then upgrade Fedora on our host system. Thanks again, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [kvm] Re: 3525MB RAM Limit
Is this a problem in the latest (kvm-84) or just in an older version that Fedora 10 provides? - Original Message - From: Daniel Scott djsc...@mit.edu To: Alex Williamson alex.william...@hp.com Cc: Brian Jackson i...@theiggy.com, kvm@vger.kernel.org Sent: Thursday, April 9, 2009 2:54:11 PM GMT -05:00 US/Canada Eastern Subject: Re: [kvm] Re: 3525MB RAM Limit Brian, Alex, 2009/4/9 Alex Williamson alex.william...@hp.com: On Thu, 2009-04-09 at 10:39 -0500, Brian Jackson wrote: some subjects to look for: * Can't boot guest with more than 3585MB when using large pages There was a patch from Marcelo that was supposed to fix it. * kvm-84 and guests with more than 3536 MB Ram? there were suggestions to make sure to use the correct bios and the OP stated that upgrading his kernel actually fixed the problem I could swear there was another one, but maybe I'm thinking of the IRC channel. If you are still unable to get it to work, you should reply back with more info. Kernel version, KVM version, etc. It could also be related to the guest trimming away memory due to the way we used to report the MTRRs. This would show up in dmesg on the guest. Try the latest kvm by hand and see if the problem goes away. Thanks for the suggestions. After more research, it looks like upgrading the software will fix the problem: http://www.func.nl/community/knowledgebase/running-kvm-guest-35-gb-ram We see the same BIOS message as in the above link. It seems like this will be fixed in Fedora 11 so we'll probably wait for a month or two and then upgrade Fedora on our host system. Thanks again, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
3525MB RAM Limit
Hi, I'm running a KVM host using Fedora 10 (x86_64) on 4x Quad-Core AMD Opteron(tm) Processor 8347 HE system with 16GB ram. I've created a Fedora 10 (x86_64) guest and allocated 8 CPUs and 8GB ram which I can see using 'virt-manager'. When I login to the guest, I can see the 8 CPUs, but apparently, I only have 3525MB RAM (output from 'free'). At first I thought it was a 32bit problem, but I've double checked and the host and guest are both running 64bit architectures. virt-manager shows 50% ram usage which appears to be correct (4GB, out of 8). It also correctly recognises the 16GB available in the host machine. Is this expected? Will the extra ram become available once it is required? If not, does anyone have any Ideas for how I can fix the problem? Thanks, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: 3525MB RAM Limit
Read the list archives. A fix was discussed recently. --Brian Jackson On Monday 06 April 2009 21:59:24 Daniel Scott wrote: Hi, I'm running a KVM host using Fedora 10 (x86_64) on 4x Quad-Core AMD Opteron(tm) Processor 8347 HE system with 16GB ram. I've created a Fedora 10 (x86_64) guest and allocated 8 CPUs and 8GB ram which I can see using 'virt-manager'. When I login to the guest, I can see the 8 CPUs, but apparently, I only have 3525MB RAM (output from 'free'). At first I thought it was a 32bit problem, but I've double checked and the host and guest are both running 64bit architectures. virt-manager shows 50% ram usage which appears to be correct (4GB, out of 8). It also correctly recognises the 16GB available in the host machine. Is this expected? Will the extra ram become available once it is required? If not, does anyone have any Ideas for how I can fix the problem? Thanks, Dan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
