>>>>> The output is on qemu's stderr. You are in control of what that stderr >>>>> is. >>>> >>>> I don't get why we can configure >>>> -D /path/to/unique/file/name.log >>>> >>>> but we also have to redirect stderr (I didn't checked if the daemonize >>>> option was closing it). What's the purpose of this logfile option? >>>> >>> >>>Well -D will log to file only loggable (i.e. qemu_log()) information >>>(which has all sorts of options and switches). Stderr, is a little >>>more static and should in theory be limited to genuine errors. But if >>>you want a combined log of both you can simply omit -D to default >>>qemu_log output to stderr. This gives you a combined log that you can >>>redirect anywhere. To be honest, this is what I do as a matter of >>>course (2> foo rather than -D foo). >>> >> Maybe we can introduce a new qemu option to specify a error logfile where >> stderr be redirected, like below, >> DEF("elogfile", HAS_ARG, QEMU_OPTION_elogfile, \ >> "-elogfile logfile redirect stderr log to logfile(default >> /var/log/qemu/<vm name>##.log)\n", >> QEMU_ARCH_ALL) >> STEXI >> @item -elogfile @var{logfile} >> @findex -elogfile >> redirect stderr in @var{logfile} >> ETEXI >> then we can set the error log file through qemu command, /var/log/qemu/<vm >> name>##.log as default. >> > >This sounds out-of-scope for QEMU to me and makes a standard flow >non-standard. If prints are going to stderr where should be going >elsewhere they probably should be fixed. Do you have specific examples >of information going to stderr that you would rather go to a log (be >it an error log or something else?). > I use proxmox to manage vm, it dose not redirect qemu's stderr, and start vm with -daemonize option, so the error log disappeared. I want to redirect the error log of qemu to a specified logfile, if fault happened, I can use the error log to analyze the fault.
And, why qemu output the error log to stderr instead of a error logfile which can be configure? Thanks, Zhang Haoyu >Regards, >Peter > >> Thanks, >> Zhang Haoyu >> >>>There's plently of tree wide work to clean up the cases where stderr >>>is used where qemu_log should be. If you are finding that log >>>information is going to stderr instead of the log, patches would be >>>welcome. >>> >>>Regards, >>>Peter