.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.\" $Id: dump.8.in,v 1.23 2001/03/23 14:40:12 stelian Exp $
+.\" $Id: dump.8.in,v 1.29 2001/07/18 13:12:33 stelian Exp $
.\"
.Dd __DATE__
.Dt DUMP 8
.Op Fl F Ar script
.Op Fl h Ar level
.Op Fl L Ar label
+.Op Fl Q Ar file
.Op Fl s Ar feet
.Op Fl T Ar date
.Op Fl z Ar compression level
-.Ar file-to-dump
+.Ar files-to-dump
.Nm dump
.Op Fl W Li \&| Fl w
.Pp
By default, the same output file name is used for each volume
after prompting the operator to change media.
.Pp
-.Ar file-to-dump
+.Ar files-to-dump
is either a mountpoint of a filesystem
-or a directory to be backed up as a subset of a filesystem.
+or a list of files and directories to be backed up as a subset of a
+filesystem.
In the former case, either the path to a mounted filesystem
or the device of an unmounted filesystem can be used.
In the latter case, certain restrictions are placed on the backup:
.Fl u
-is not allowed and the only dump level that is supported is
-.Fl 0 .
+is not allowed, the only dump level that is supported is
+.Fl 0
+and all the files and directories must reside on the same filesystem.
.Pp
The following options are supported by
.Nm Ns :
last dump of a lower level.
The default level is 9.
.It Fl B Ar records
-The number of 1 KB blocks per volume.
+The number of 1 kB blocks per volume.
This option overrides the end-of-media detection, and calculation
-of tape size based on length and density.
+of tape size based on length and density. If compression is on this
+limits the size of the compressed output per volume.
.It Fl a
.Dq auto-size .
Bypass all tape length calculations, and write
.It Fl b Ar blocksize
The number of kilobytes per dump record.
Since the IO system slices all requests into chunks of MAXBSIZE
-(typically 64KB), it is not possible to use a larger blocksize
+(typically 64kB), it is not possible to use a larger blocksize
without having problems later with
.Xr restore 8 .
Therefore
.Nm
should continue without asking the user to change the tape, 1 if
.Nm
-dump should continue but ask the user to change the tape.
+should continue but ask the user to change the tape.
Any other exit code will cause
.Nm
to abort.
.Dq operator
by means similar to a
.Xr wall 1 .
+.It Fl Q Ar file
+Enable the Quick File Access support. Tape positions for each
+inode are stored into the file
+.Ar file
+which is used by restore (if called with parameter Q and the filename)
+to directly position the tape at the file restore is currently working
+on. This saves hours when restoring single files from large backups,
+saves the tapes and the drive's head.
+.Pp
+It is recommended to set up the st driver to return logical tape
+positions rather than physical before calling dump/restore with
+parameter Q. Since not all tape devices support physical tape
+positions those tape devices return an error during dump/restore when
+the st driver is set to the default physical setting.
+Please see the st man page, option MTSETDRVBUFFER, or the mt man
+page, on how to set the driver to return logical tape positions.
+.Pp
+Before calling restore with parameter Q, always make sure the st
+driver is set to return the same type of tape position used during the
+call to dump. Otherwise restore may be confused.
.It Fl s Ar feet
Attempt to calculate the amount of tape needed at a particular density.
If this amount is exceeded,
reels already written just hang around until the entire tape
is written.
.Pp
+The estimated number of tapes is not correct if compression is on.
+.Pp
It would be nice if
.Nm
knew about the dump sequence,
git.wh0rd.org / dump.git / blobdiff