On Wed, May 17, 2017 at 4:20 PM, Jerry <jerryubi at gmail.com> wrote: > On Wed, May 17, 2017 at 2:39 AM, George Dunlap <dunlapg at umich.edu> wrote: >> >> On Wed, May 17, 2017 at 4:26 AM, Jerry <jerryubi at gmail.com> wrote: >> > I always disable "rhgb quiet" on a fresh install because I don't like >> > boot >> > messages being hidden from me, and now this other thing does it. I like >> > details, I need the details, don't hide them from me. >> >> I feel the same way about 'rhgb quiet'. :-) >> >> The 'console=hvc0' setting doesn't hide them from you, it just sends >> them somewhere you're not looking. > > > I'm looking at the system's console during installation. Sending it > somewhere else is hiding it from me. > >> >> On bare metal, the console output can typically go two places: >> 1. The screen >> 2. A serial port >> >> For server applications serial has several advantages over the screen: >> * You can capture the output to more easily report bugs >> * If you're capturing it you can keep things that would have scrolled >> off-screen, or been erased due to a reboot >> * In a datacenter it's faster, more convenient, and cheaper than an >> IP-based KVM switch > > > I get what these things are, but not what hvc0 is doing. See below -- it sends the output to Xen; Xen will then forward it to the serial, the screen, or both. > This system has built-in IPMI, the installation was done remotely using it. > >> >> Xen has the same two options above; but when Linux is running as a >> dom0 under Xen, there are three places to put it: >> 1. The screen >> 2. A serial line >> 3. Send it to Xen to put wherever Xen is putting it >> >> #1 is easy, but #2 is tricky because Xen is likely to be already using >> the serial port you want to use. >> >> "console=hvc0" is #3. >> >> What's your Xen command-line look like? The default should be >> "console=com1,tty", so Xen's output should show up both places (and so >> should Linux's if it's set to console=hvc0). > > > This is what's defined in /etc/default/grub following the install of the > Xen: > > GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M cpuinfo com1=115200,8n1 > console=com1,tty loglvl=all guest_loglvl=all" > GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT="console=hvc0 earlyprintk=xen > nomodeset" > > I didn't set these myself, this is what the xen package (or one of its > dependencies) is doing. It's the CentOS Xen package setting this. But the Xen option "console=com1,tty" should make it such that Xen sends its output *both* to the serial line, *and* the monitor. I take it you're not seeing any Xen output at all on your IPMI console? -George