On Thu, Sep 16, 2010 at 11:40:43AM +0200, Michael Sperber wrote: > Stefan Bethke <s...@lassitu.de> writes: > > Am 16.09.2010 um 11:05 schrieb Michael Sperber: > > > >> I just upgraded my desktop system from 7.3 to 8.1, and the main hard > >> drive, which was /dev/ad6 before is now /dev/ad10. Consequently, the > >> initial boot failed when trying to mount the root file system from ad6. > >> > >> The desktop system is now fixed, but I also have a rented server with > >> only a serial console, and I worry that the upgrade is going to leave me > >> with a dead machine. Is there any way to predict how the drive number > >> changes? (Why does it change at all?) If so, what's the proper way to > >> tell the system the initial root device *before* rebooting? > > > > If you have a serial console, you can always enter the root device at > > the prompt, so you can recover there. > > I know. But given the serial-console problems recently reported here, I > was a bit reluctant to take the risk.
I assume you're referring to the issue reported by Oliver Fromme. That issue may -- not 100% certain at this point -- be related to the DCD line on a serial port being used/honoured by uart(4). We have numerous systems using RELENG_8 with reliable/working serial console, but as I stated in the other thread, our wiring/equipment and adapters differ from Oliver's. I still have not tested the patch Ed provided due to my day (night) job keeping me busy the past 24-48 hours. I'll see if I can get to testing it tonight. The only reason I'm testing the patch, by the way, is to see if *our* stuff suddenly breaks -- and if it does, I can still roll it back remotely (via serial console). Soapbox, for what it's worth: Serial console unreliability and OS installs are both reasons why I rent co-location space that's local to me (within driving distance). I cannot imagine having servers in another state or country which only have serial console (e.g. PXE is not configured in the BIOS, BIOS lacks serial redirection, no remote rebooter/power-cycle unit, no dial-in modem, etc.). Depending on how mission-critical your setup is, I would highly recommend investing the time and money into a setup that does allow access to the servers when serial console breaks -- an KVM-over-IP device would be ideal, since it gives you VGA console via VNC or a Java client. In my case I'm just a single guy with a bunch of servers, and run what I do as a (expensive) hobby. KVM-over-IP devices are unreasonably overpriced (like most "enterprise-grade" things), and I tend to shy away from HP/Compaq ProLiant hardware (which have LOM/LOM2) since over the years I've seen too many problems with them posted on the FreeBSD lists (mainly relating to storage device driver problems), not to mention the support contract costs... -- | Jeremy Chadwick j...@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB | _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
