X-Git-Url: https://git.wh0rd.org/?p=dump.git;a=blobdiff_plain;f=dump%2Fdump.8.in;h=1cc17231e49bcf5bc8068227f9732f070f59d697;hp=1245d849325163b82d1fb1ce4be7836a20fe79bf;hb=f39dae9975f9d3480f18eed5c7660e38fe332a97;hpb=ae6919a74c79344882403cd9288ebc4dd0bcd4a2 diff --git a/dump/dump.8.in b/dump/dump.8.in index 1245d84..1cc1723 100644 --- a/dump/dump.8.in +++ b/dump/dump.8.in @@ -26,14 +26,15 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" $Id: dump.8.in,v 1.55 2004/02/18 16:26:41 stelian Exp $ +.\" $Id: dump.8.in,v 1.61 2009/06/18 09:36:52 stelian Exp $ .\" .TH DUMP 8 "version __VERSION__ of __DATE__" BSD "System management commands" .SH NAME dump \- ext2/3 filesystem backup .SH SYNOPSIS .B dump -[\fB\-0123456789ackMnqSuv\fR] +[\fB\-\fIlevel#\fR] +[\fB\-ackMnqSuv] [\fB\-A \fIfile\fR] [\fB\-B \fIrecords\fR] [\fB\-b \fIblocksize\fR] @@ -56,9 +57,6 @@ dump \- ext2/3 filesystem backup .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 @@ -88,15 +86,17 @@ and all the files and directories must reside on the same filesystem. The following options are supported by .B dump: .TP -.BI \-0\-9 -Dump levels. A level 0, full backup, guarantees the entire file system is -copied (but see also the +.BI \-level# +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. +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 \*(lqauto-size\*(rq. Bypass all tape length calculations, and write until an @@ -284,6 +284,12 @@ Inodes which are either directories or have been modified since the last dump 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. @@ -515,8 +521,8 @@ Always start with a level 0 backup, for example: 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 @@ -528,6 +534,15 @@ set of tapes per dumped file system is used, also on a cyclical basis. .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