On 8/27/19 9:58 AM, Seema Pandit wrote: > error: internal error: qemu unexpectedly closed the monitor: ftruncate: > Invalid argument 2019-08-22T04:16:08.744402Z qemu-system-x86_64: -object > memory-backend-file,id=memnvdimm0,prealloc=yes,mem-path=/dev/dax1.0,size=403726925824: > unable to map backing store for guest RAM: Cannot allocate memory I wonder if dropping 'prealloc' would help. This error message comes from phase before 'prealloc' is processed. You can try the following patch: diff --git i/src/qemu/qemu_command.c w/src/qemu/qemu_command.c index 373ebd6d1a..c375955eab 100644 --- i/src/qemu/qemu_command.c +++ w/src/qemu/qemu_command.c @@ -3468,7 +3468,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, } if (virJSONValueObjectAdd(props, - "B:prealloc", prealloc, + "B:prealloc", prealloc ? false : false, "s:mem-path", memPath, NULL) < 0) goto cleanup; Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list