I had temporarily started a VM, and it has allocated the memory for it. I have realised that after turning it down, the memory allocated to it, has remained reserved. Now, I need it for Dom0. So, how do I release the RAM that is reserved for VM, and make it available to Dom0? Is reboot the only option? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I had temporarily started a VM, and it has allocated the memory for it. I have realised that after turning it down, the memory allocated to it, has remained reserved. Now, I need it for Dom0. So, how do I release the RAM that is reserved for VM, and make it available to Dom0? Is reboot the only option? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Rakesh Chawda wrote:>I had temporarily started a VM, and it has allocated the memory for >it. I have realised that after turning it down, the memory allocated >to it, has remained reserved. Now, I need it for Dom0. >So, how do I release the RAM that is reserved for VM, and make it >available to Dom0? Is reboot the only option?Changing the config won''t affect a running DomU. Just a reboot won''t help either - it needs to be a shutdown and then start it again. But for memory, you can use xm mem-set to reduce memory usage in a running guest using the balloon driver. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
My problem, I want to turn off all the DomUs, and allocate all the ram back to Dom0. Even if I turn the DomU down, the memory still remains allocated to them. On Sun, Aug 28, 2011 at 5:48 PM, Simon Hobson <linux@thehobsons.co.uk>wrote:> Rakesh Chawda wrote: > >> I had temporarily started a VM, and it has allocated the memory for it. I >> have realised that after turning it down, the memory allocated to it, has >> remained reserved. Now, I need it for Dom0. >> So, how do I release the RAM that is reserved for VM, and make it >> available to Dom0? Is reboot the only option? >> > > Changing the config won''t affect a running DomU. Just a reboot won''t help > either - it needs to be a shutdown and then start it again. > > But for memory, you can use xm mem-set to reduce memory usage in a running > guest using the balloon driver. > > -- > Simon Hobson > > Visit http://www.**magpiesnestpublishing.co.uk/<http://www.magpiesnestpublishing.co.uk/>for books by acclaimed > author Gladys Hobson. Novels - poetry - short stories - ideal as > Christmas stocking fillers. Some available as e-books. > > ______________________________**_________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/**xen-users<http://lists.xensource.com/xen-users> >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Rakesh Chawda wrote:>My problem, I want to turn off all the DomUs, and allocate all the >ram back to Dom0. Even if I turn the DomU down, the memory still >remains allocated to them.No it doesn''t. When you shut down a DomU then the memory it was using is returned to Xen''s memory pool. I think you need to describe your setup and problem in more detail. How/where are you measuring free memory ? Have you configured Dom0 to use a specific memory allocation (as is generally recommended) ? What tools are you using ? Native Xen tools or some management layer on top ? And of course, what versions/distro ? -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Details: OS: Centos 5.6 Ram 16GB in all Processor: 4core with HT (8 Threads) Xen Management: XM Problem: I use "xm top" to view the current status of all the VMs. The first VM (vm01) is of 4GB RAM. I could see complete ram allocated to Dom0 when I had rebooted the server. Once I started the vm01, it took 4GB ram toitself as it was told. Its work was over, and I have shut it down. Now, I still see 12GB allocated to Dom0, inspite of shutting down vm01, which I have seen until now. I would like the 4GB unused ram to be allocated to Dom0 without restarting, as it cannot be done now. My application runs on Dom0, and I am planning not use VMs on this machine in the future, which explains why need full RAM for Dom0. I can see this in xm top: Mem: 16686296k total, 12491528k used, 4194768k free CPUs: 8 @ 3411MHz and this in top on Dom0 Mem: 12142592k total @Alexandre: Following is the output of the command you specified: # xm mem-set Domain-0 0 Error: Invalid memory size I also tried: # xm mem-set 0 Domain-0 Error: Invalid argument. Thanks for prompt responses guys, I have tried searching the internet to no avail. On Sun, Aug 28, 2011 at 9:38 PM, Alexandre Chapellon <a.chapellon@horoa.net>wrote:> Do0 is a domain and xm is the tool to manage domain resssource > allocation... > > have you tried xm mem-set 0 xxx? > > Should work! > > Le 28/08/2011 14:41, Simon Hobson a écrit : > > Rakesh Chawda wrote: >> >>> My problem, I want to turn off all the DomUs, and allocate all the ram >>> back to Dom0. Even if I turn the DomU down, the memory still remains >>> allocated to them. >>> >> >> No it doesn''t. When you shut down a DomU then the memory it was using is >> returned to Xen''s memory pool. >> >> I think you need to describe your setup and problem in more detail. >> >> How/where are you measuring free memory ? >> Have you configured Dom0 to use a specific memory allocation (as is >> generally recommended) ? >> What tools are you using ? Native Xen tools or some management layer on >> top ? >> And of course, what versions/distro ? >> >> > -- > <http://www.horoa.net> > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Rakesh Chawda wrote:>@Alexandre: >Following is the output of the command you specified: ># xm mem-set Domain-0 0 >Error: Invalid memory size > >I also tried: ># xm mem-set 0 Domain-0 >Error: Invalid argument.Did you consider giving valid arguments ? Alexandre said :>have you tried xm mem-set 0 xxx?0 is the domain - note "0", not "Domain-0". xxx needs replacing with the memory allocation (I think in MByte, neither the command help nor man page include this bit of information). But since your plan is to not use Xen on this machine, you should reboot into a native kernel and remove the overheads running under the hypervisor imposes. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users