Unix Backup and Recovery

Backing Up with the dump Utility

For many environments, dump may be all you need to ensure good-quality backups. To use dump and restore for regular system backups, you need to understand the following:

• How to use dump to back up a filesystem (with the appropriate options)

• How the backup ends up on the volume

• How to get the table of contents of a dump volume

• How to manipulate the volume and restore from a backup created by dump

• The limitations of dump and restore

• What you should be doing if you are using dump on a regular basis

The first thing to understand is what your dump command is and what its options are. See Table 3-1 for a listing of dump commands on various Unix versions. What follows is essentially a unified manpage for these dump -like commands on specific operating systems.

Table 3-1. dump-Like Commands on Different Unix Versions

HP-UX 9.x HP-UX 10 SunOS IRIX	Solaris	SCO	Network Appli-ance	AIX	Linux	SGI	Tru64 Unix
(r)dump	ufsdump	xdump [a]	dump	backup and rdump	dump	dump and xfsdump [b]	dump and vdump
[a] SCO’s xdump, a link to xbackup, works only with XENIX filesystems. There is another command, called backup , which is really a link to cpio, which works with non-XENIX filesystems. SCO’s xdump is also missing two options—the b “blocking factor” and the n “notify” options—which are standard on other Unix systems. SCO’s xdump does not support remote devices. Its companion, xrestore , is also quite different from the other versions of