my original question concerned shutting down a system unattended for
system backups, and then bringing it back up to multiuser mode again.
i could not figure out a way to do this without completely bringing
the system down (and killing my backup script in the process.) i
received many answers to my question, which pretty much fell into two
groups. one group of people said that it is completely unnecessary
to do this when using ufsdump for backups, the system can be in
multiuser mode and it's OK if filesystems are mounted. just make
sure that there isn't excessive disk activity, and it would be better
if users weren't logged in.
the other group of people suggested ways for doing the shutdown and
then recovering from it. nearly every answer i recieved centered on
/etc/rc?.d (system startup) scripts. from what i can tell, the best
way to do what i want is to have a crontab entry touch some file
somewhere, and then do a complete shutdown and reboot. put a script
in /etc/init.d that will check for the file and do the backups. link
the script into /etc/rc2.d in the appropriate place so that it will
be run before the system comes up into complete multiuser mode.
after examining my requirements, and running some tests on a loaded
system, i decided that running ufsdump without shutting the system
down is 'good enough' for me. since i run dumps every night, i'd
prefer not to have to reboot the system every day, and no-one in our
company should be on the machines after 5:00. even if someone is
working *very* late, and manages to get part of one of the backups
corrupted, there will be another dump the next day anyway. but, i
find this highly unlikely. ufsdump was able to deal with dumping a
mounted, moderately active filesystem with no problems.
i would like to thank all of the following kind people for responding
to my question, and helping me to make my decision:
Rich Kulawiec
Herbert Wengatz
Richard Butler
Brian Styles
Keith Willenson
Glenn Satchell
Adnan Dzinic
Jim Harmon
John Benjamins
Michael Sullivan
David Gillam
Brian T. Wightman
Alfredo Sola
Michael Maciolek
Syed Zaeem Hosain
orr@ccsmtp2.eecs.com (real name?)
thanks again for your help.
-- Matthew J. Hill hill@graver.com
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:11:17 CDT