Why idle backups?? (was Re: Looking for shell script for backup on BSD 4.3)

[Aydin Edguer]

In article <32762 at sparkyfs.istc.sri.com> zwicky at pterodactyl.erg.sri.com.UUCP (Elizabeth Zwicky) writes:
>In article <1990Oct24.210312.3271 at cubmol.bio.columbia.edu> ping at cubmol.bio.columbia.edu (Shiping Zhang) writes:
>>In article <32749 at sparkyfs.istc.sri.com> zwicky at quetzalcoatl.erg.sri.com.UUCP (Elizabeth Zwicky) writes:
>>>You should give serious
>>>thought to running level 0s in single-user; you can do this
>>>automatically in the middle of the night by using the same sort of
>>>trick that fastboot uses, creating a magic file that the rc files
>>>look for in the boot process to tell them to do backups.
>
>>I have seen this suggestion more than once on this news group.
>>But I don't know how. One question I have is about the tape changes.
>>Certainly one tape is not enough for a zero level backup.
>>How to get away with this problem?  Thanks for any enlightenment.

I would like to suggest that going to single-user for a level 0 backup is
unnecessary.  All that really needs to be done is to unmount the (4.2/ufs)
file system.  This means that the computer can continue to function and
even serve diskless clients (as long as you are not backing up /export).
This permits the whole thing to be done in a script from "cron" or "at" without
mucking with your rc files.  The only file system that may not be backed
up in this manner is the root partition.  /usr is normally (SunOS4.1) read-only
and thus does not need to be backed up.

Aydin Edguer