Wrong use of the parentheses causes "rc" always having a boolean value, either "1" or "0", and thus we can't get the detailed error message when it fails: Before (I only have 1 node): % virsh numatune f18 --nodeset 12 error: Unable to change numa parameters error: unable to set numa tunable: Unknown error -1 After: virsh numatune f18 --nodeset 12 error: Unable to change numa parameters error: unable to set numa tunable: Invalid argument --- src/qemu/qemu_driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index cee5557..0de7ffd 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -7470,7 +7470,7 @@ qemuDomainSetNumaParameters(virDomainPtr dom, continue; } - if ((rc = virCgroupSetCpusetMems(priv->cgroup, nodeset_str) != 0)) { + if ((rc = virCgroupSetCpusetMems(priv->cgroup, nodeset_str)) != 0) { virReportSystemError(-rc, "%s", _("unable to set numa tunable")); virBitmapFree(nodeset); -- 1.8.1.4