.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.\" $Id: dump.8.in,v 1.56 2004/04/21 08:55:48 stelian Exp $
+.\" $Id: dump.8.in,v 1.62 2009/06/18 09:40:03 stelian Exp $
.\"
.TH DUMP 8 "version __VERSION__ of __DATE__" BSD "System management commands"
.SH NAME
.PP
.B dump
[\fB\-W \fR| \fB\-w\fR]
-.PP
-(The 4.3BSD option syntax is implemented for backward compatibility but is not
-documented here.)
.SH DESCRIPTION
.B Dump
examines files on an ext2/3 filesystem and determines which files need to be
.B dump:
.TP
.BI \-level#
-The dump level (any integer). A level 0, full backup, guarantees the
-entire file system is copied (but see also the
+The dump level (any integer). A level 0, full backup, specified by
+.B \-0
+guarantees the entire file system is copied (but see also the
.B \-h
option below). A level number above 0, incremental backup, tells
.B dump
to
copy all files new or modified since the last dump of a lower level. The
-default level is 9. Historically only levels 0 to 9 were usable in
+default level is 0. Historically only levels 0 to 9 were usable in
dump, this version is able to understand any integer as a dump level.
.TP
.BI \-a
are saved in a regular way. Uses of this flag must be consistent, meaning that
either every dump in an incremental dump set have the flag, or no one has it.
.IP
+If you use this option, be aware that many programs that unpack
+files from archives (e.g. tar, rpm, unzip, dpkg) may set files'
+mtimes to dates in the past. Files installed in this way may not be
+dumped correctly using "dump -m" if the modified mtime is earlier
+than the previous level dump.
+.IP
Tapes written using such 'metadata only' inodes will not be compatible with the
BSD tape format or older versions of
.B restore.
.B dump
to print out, for all file systems in
.I __DUMPDATES__ ,
-and regognized file systems in
+and recognized file systems in
.I /etc/mtab
and
.IR /etc/fstab .
This should be done at set intervals, say once a month or once every two months,
and on a set of fresh tapes that is saved forever.
.IP \(em
-After a level 0, dumps of active file systems are taken on a daily basis, using
-a modified Tower of Hanoi algorithm, with this sequence of dump levels:
+After a level 0, dumps of active file systems are taken on a daily basis,
+with this sequence of dump levels:
.RS 14
.B 3 2 5 4 7 6 9 8 9 9 ...
.RE
.PP
After several months or so, the daily and weekly tapes should get rotated out
of the dump cycle and fresh tapes brought in.
+.PP
+Another backup strategy is the Tower of Hanoi sequence, which reuses
+older tapes in a way that for newer dates the available restore points
+are more frequent, then for older dates (see
+http://en.wikipedia.org/wiki/Backup_rotation_scheme for additional
+information).
+.PP
+(The 4.3BSD option syntax is implemented for backward compatibility but is not
+documented here.)
.SH ENVIRONMENT
.TP
.B TAPE
.B dump
provided that the machine on which
.B dump
-is run did not change timezones (which should be a fairly rare occurence).
+is run did not change timezones (which should be a fairly rare occurrence).
.SH EXIT STATUS
.B Dump
exits with zero status on success. Startup errors are indicated with an exit
When a read error occurs,
.B dump
prints out the corresponding physical disk block and sector number and the
-ext2/3 logical block number. It doesn't print out the corresponing file name or
+ext2/3 logical block number. It doesn't print out the corresponding file name or
even the inode number. The user has to use
.BR debugfs (8),
commands
backup suite was ported to Linux's Second Extended File System by Remy Card
<card@Linux.EU.Org>. He maintained the initial versions of
.B dump
-(up and including 0.4b4, released in january 1997).
+(up and including 0.4b4, released in January 1997).
.PP
Starting with 0.4b5, the new maintainer is Stelian Pop <stelian@popies.net>.
.SH AVAILABILITY
git.wh0rd.org / dump.git / blobdiff