On 2014/9/28 16:19, Jincheng Miao wrote: > > On 09/28/2014 01:38 PM, Linhaifeng wrote: >> >> On 2014/9/25 2:05, Eric Blake wrote: >>> On 09/24/2014 02:05 AM, Linhaifeng wrote: >>>> Hi, >>>> >>>> I want to use virsh to create a VM with the qemu parameter '-object memory-backend-file,id=mem,size=2048M,mem-path=/mnt/huge,share=on -numa node,memdev=mem'. >>> Looking at tests/qemuxml2argvdata/qemuxml2argv-hugepages-pages.args, I >>> see several instances of "-object memory-backend-file...", so look at >>> the counterpart .xml file for some examples: >>> >>> <memoryBacking> >>> <hugepages> >>> <page size='2048' unit='KiB' nodeset='1'/> >>> <page size='1048576' unit='KiB' nodeset='0,2-3'/> >>> </hugepages> >>> </memoryBacking> >>> >>> >> Thank you. >> >> I use this xml: >> <cpu> >> <numa> >> <cell id='0' cpus='0' memory='1073741824' memAccess='shared'/> >> <cell id='1' cpus='1' memory='1073741824' memAccess='shared'/> >> </numa> >> </cpu> >> <memoryBacking> >> <hugepages> >> <page size="2" unit="M" nodeset="0,1"/> >> </hugepages> >> </memoryBacking> >> >> but there is also some error: >> [2014-09-28T05:28:32.373335Z] migration_configure:652 Parameter 'cache size' expects exceeds guest ram size >> [2014-09-28T05:28:32.373422Z] main:3517 start memory options parse >> 2014-09-28T05:28:32.373802Z qemu-kvm: -object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1048576M,id=ram-node0: unable to map backing store for hugepages: Cannot allocate memory >> 2014-09-28T05:28:32.373895Z qemu-kvm: -object memory-backend-file,prealloc=yes,mem-path=/dev/hugepages/libvirt/qemu,size=1048576M,id=ram-node1: unable to map backing store for hugepages: Cannot allocate memory > > get total number of the hugepages you could use: > # cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages > > From your xml: > <cell id='0' cpus='0' memory='1073741824' memAccess='shared'/> > <cell id='1' cpus='1' memory='1073741824' memAccess='shared'/> > I guess your machine doesn't have so much hugepage memory: sum(1073741824 + 1073741824)=2048G !!! > Thank you. Yes,you are right.This is my mistake.Actually i want to use 1G. >> >> _______________________________________________ >> libvirt-users mailing list >> libvirt-users@xxxxxxxxxx >> https://www.redhat.com/mailman/listinfo/libvirt-users > > _______________________________________________ > libvirt-users mailing list > libvirt-users@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvirt-users > > _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
