mitchell@cadovax.UUCP (Mitchell Lerner) (03/16/88)
Lets say my passwd or inittab file or something gets clobbered so that
my system won't come up multiuser.
How do I bring up Xenix 2.2.1 in some sort of stand alone or single user
mode so that I can do things like:
o mount file systems.
o look around.
o edit files.
o cpio or tar stuff in.
In this mode will I still be able to use my 9 track cartrige tape drive
to restore things?
which works better for getting specific stuff off (e.g. /u/osas/data/* or
/usr/bin/???), cpio or tar)? I had some trouble doing this with tar
but it may have been attributed to some other tape trouble that I was
haveing at the time. I would think that you could do this with either.
Which is better to use for daily backup/restore functions (cpio or tar)?
Thanks.
--
Mitchell Lerner
UUCP: {ucbvax,ihnp4,decvax}!trwrb!cadovax!mitchell
"When I fight with my mind, my mind always wins" - Ben Hummeljack@turnkey.TCC.COM (TCC Software Developer) (03/18/88)
In article <1990@cadovax.UUCP> mitchell@cadovax.UUCP (Mitchell Lerner) writes: > >Lets say my passwd or inittab file or something gets clobbered so that >my system won't come up multiuser. > >How do I bring up Xenix 2.2.1 in some sort of stand alone or single user >mode Unless you have modified or are using a modified init with your Xenix runtime you should be asked to enter a password for system maintenance mode or to hit Control D for multi-user mode. If you enter the root or sysadm password at that point you will be in single-user mode and will be able to do all the things you asked about. If you are using a modified init (one that uses a REAL SysV inittab) what you would do is have a Run Level 1 in which the /etc/rc file is not executed, thus cron and other multiuser processes will not be started, enter that run level to do the things you describe. As to what to do about a clobbered passwd file (inittab would hardly matter with SCO's present implementation), the best approach would be to have a bootable floopy, in fact this is an indispensible tool, if you don't have at least one around MAKE ONE NOW! This is done using the command 'mkdev fd', see the manual for details. I found that I needed to add and delete certain things to make it really useful. Then you need to boot from it and run divvy on the primary hard drive, you will see the root file system in terms of its blocks but it will have no name (this is because you are now in the 'root' of the floppy), give it some name like hdroot or foo and exit divvy. You can now mount that file system onto the floppy (mount /dev/foo /mnt) and make any necessary repairs or alterations. Be forwarned however that the big weakness with bootable floppies is that they have a very small swap space and will panic easily if you run large processes like vi, even ls'ing a directory has caused this. It is an emergency tool, keep things on it like a reduced passwd file so you could cp it onto the hard drive if necessary. >which works better for getting specific stuff off (e.g. /u/osas/data/* or >/usr/bin/???), cpio or tar)? I find tar more convenient for access to specific items from a backup, its one weakness is that wildcards do not work on extraction. This is easy enough to get around however. I would always suggest backups with multiple formats in any case. Hope this helps, -- Jack F. Vogel Turnkey Computer Consultants, Costa Mesa, CA UUCP: ...!uunet!turnkey!jack Internet: jack@turnkey.TCC.COM
ag@portnoy.CTS.COM (Keith Gabryelski) (03/19/88)
In article <152@turnkey.TCC.COM> jack@turnkey.TCC.COM (Jack F. Vogel) writes: >In article <1990@cadovax.UUCP> mitchell@cadovax.UUCP (Mitchell Lerner) writes: >>which works better for getting specific stuff off (e.g. /u/osas/data/* or >>/usr/bin/???), cpio or tar)? > >I find tar more convenient for access to specific items from a backup, its >one weakness is that wildcards do not work on extraction. This is easy >enough to get around however. I would always suggest backups with multiple >formats in any case. I didn't get the message that Jack was repling to (head crash ate 3 days of news), but from the paragraph above I think some points should be added. tar will not archive FIFOs or devices. cpio will. If your intent is to backup the entire system including special files then you would probably want to use cpio. tar, ofcourse, is more portable and thus, for moving files from one machine to another would be your better (sometimes only) choice. Pax, Keith -- [ Keith ] UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!portnoy!ag [Gabryelski] INET: ag@portnoy.cts.com ARPA: crash!portnoy!ag@nosc.mil