Q:  What is a good strategy for backing up a system?

A:  The following is a suggested method of backing up a system using dump(8).

1. Install and configure the software on the system as desired.
2. Generate files depending solely on the release:
cat pages--catman(8).
Index the header files (/usr/include)--Digital Librarian.
Install desired packages from the CD-ROM.
3. Perform a phony level 0 dump (use one of the following):
dump 0uf /dev/null /dev/rsd0a
Takes longer
Simpler
Edit the file /etc/dumpdates
Takes less time
Slightly more complicated
Put a line such as the following in the file:

/dev/rsd0a       0 Tue Sep 19 12:19:40 1989

The easiest way to get such a line truely properly formatted is to copy another one.  Format [from dumpdates(5)]:

"-16%s %c %s"

Key: those blanks are not tabs!

4. Configure the system (NetInfo, restore users, etc.).
5. Perform a level 1 dump.
Phony if everything is simply restored.
Real if work was needed.

mount /dev/od0a /DUMP
dump 1ufo /DUMP/clients-1.dump /dev/rsd0b
umount /dev/od0a
disk -e /dev/rod0a

The file name clients-1.dump is based on the file system name (where it's usually mounted; here, assumed to be /clients) and the dump level.

6. PUT THE RELEASE DISK, THE UPGRADE DISK, AND THE LEVEL 1 DUMP IN A VERY SAFE PLACE.  It even makes sense to make a second level 1 dump.
Now you're ready for normal operations.
7. Each day, perform an incremental dump.
Level 9.
Rotate media each day (multiple sets precludes destroying the most recent dump if today's dump fails).
8. Each week, do a weekly dump
On the first week of the month, do a level n dump:
n is 1 if there was no configuration work done.
n is 2 if configuration work was done.
The second week, do a level n+1 dump.
Etc.
Rotate media, using at least two sets.
9. Each month, do a monthly dump.
A monthly dump is a level n dump (n as in step 8).
Rotate media, using at least two sets
10. Repeat the cycle, rotating media using at least two sets.

QA416

Valid for 1.0, 2.0, 3.0, 3.1