db817b8c50
The '-trace' and '--trace' spellings are only both supported in qemu binary, while for qemu-nbd or qemu-img only '--trace' spelling is supported. So for the consistency of trace option invocation, we should use double-dash spelling in our documentation. This's also mentioned in https://wiki.qemu.org/BiteSizedTasks#Consistent_option_usage_in_documentation . Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1530674247-31200-1-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>