Date: Fri, 2 Mar 2012 12:31:28 +0000 (UTC) From: jb <jb.1234abcd@gmail.com> To: freebsd-current@freebsd.org Subject: Re: revisiting tunables under Safe Mode menu option Message-ID: <loom.20120302T132758-79@post.gmane.org> References: <4F26CC5A.2070501@FreeBSD.org> <4F4C0600.2000903@FreeBSD.org> <3BA1B476-ED05-4E8E-8DFA-0B06EFB48867@samsco.org> <201202280846.08966.jhb@freebsd.org> <A8C72CB9-4C77-4697-8C28-63A2E10C557D@fisglobal.com> <4F4F35B9.5090308@FreeBSD.org> <06bb01ccf7cb$b255a200$1700e600$@fisglobal.com> <4F4FE85D.4070205@freebsd.org> <074701ccf7f3$315cca20$94165e60$@fisglobal.com> <4F4FEF85.2050308@freebsd.org> <075601ccf7f9$47b0fac0$d712f040$@fisglobal.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Devin Teske <devin.teske <at> fisglobal.com> writes:
> ...
> > > So I would welcome discussions involving development of something better
> > (and am
> > > willing to help).
> >
> ...
> Not exactly sure what "service safemode start" should do (BSD doesn't have the
> same concept of runlevels as Linux does; so it's not exactly intuitive to think
> we could go from multi-user mode *into* safe mode).
>
> But "service safemode status" would be interesting.
>
> Interestingly, it would perhaps be nice if "service safemode stop" brought the
> system back to fully usable without need for reboot (something Windows doesn't
> offer).
I looked around the Internet and collected some sound bites:
- Safe Mode
- it forces a check of startup (root) partition.
- you have access to only minimal number of basic files and drivers (mouse,
monitor, keyboard, mass storage, base video, fonts, default system
services, and no network connections).
If your computer does not start successfully using Safe Mode, you might
need to use the Safe Mode with Root Shell feature to repair your system.
- it disables all startup items and login items
- it has to delete (and eventually recreate) any shared caches (dynamic
loader, dynamic libraries, etc)
- it enables boot logging
The boot log is useful in determining the exact cause of system startup
problems.
Log all drivers and services that were loaded (or not loaded) by the system
to a file.
- what about remote fs (NFS, etc) ?
- it helps you diagnose problems.
If a symptom does not reappear when you start in safe mode, you can
eliminate the default settings and minimum device drivers as possible
causes.
If a newly added device or a changed driver is causing problems, you can
use safe mode to remove the device or reverse the change.
The same with newly installed packages.
- enabled debugging mode
It may be preconfigured for debugging mode with info to be sent across
a serial cable to another computer that is running a debugger.
- enabled networking mode (optional)
This to allow remote safe mode.
- startable from a local or remote terminal, on a command line.
In case of a remote startup it would require networking mode enabled.
- boot verbosity mode (full, regular, minimal, none)
- logging verbosity mode (full, regular, minimal, none)
- option to return to boot menu (loader)
- option to reboot
- Safe Mode with Root Shell
Like regular Safe Mode with boot into root shell (like Single User Mode,
with configurable root password requirement).
This mode is particularly useful if you need to repair your system by
copying a file from a CD-ROM to your hard drive, or if you need to
reconfigure a service that is preventing your computer from starting
properly.
This functionality is indeed similar to Single User Mode, but after further
considerations it may be different under Safe Mode.
jb
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?loom.20120302T132758-79>