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author | joerg <joerg@FreeBSD.org> | 1997-02-01 23:44:19 +0000 |
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committer | joerg <joerg@FreeBSD.org> | 1997-02-01 23:44:19 +0000 |
commit | 2b3e3d73631a489bffa4a50c304657e955ecca99 (patch) | |
tree | dc76471edeb31d300aec417640c523cda78aa232 /sbin/dump/dump.8 | |
parent | b0c88e4d210ce20c6d868495b891852c3939afa6 (diff) | |
download | FreeBSD-src-2b3e3d73631a489bffa4a50c304657e955ecca99.zip FreeBSD-src-2b3e3d73631a489bffa4a50c304657e955ecca99.tar.gz |
Add the `a' option (``auto-size'') to bypass all tape length
considerations, and dump right to the end of medium.
Diffstat (limited to 'sbin/dump/dump.8')
-rw-r--r-- | sbin/dump/dump.8 | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/sbin/dump/dump.8 b/sbin/dump/dump.8 index 13a69e4..40b257a 100644 --- a/sbin/dump/dump.8 +++ b/sbin/dump/dump.8 @@ -41,7 +41,7 @@ .Nd filesystem backup .Sh SYNOPSIS .Nm dump -.Op Cm 0123456789BbhfusTdWn Op Ar argument ... +.Op Cm 0123456789BTWabcdfhnsu Op Ar argument ... .Op Ar filesystem .Sh DESCRIPTION .Nm Dump @@ -56,7 +56,11 @@ option below for doing remote backups). A dump that is larger than the output medium is broken into multiple volumes. On most media the size is determined by writing until an -end-of-media indication is returned. +end-of-media indication is returned. This can be enforced +by using the +.Cm a +option. +.Pp On media that cannot reliably return an end-of-media indication (such as some cartridge tape drives) each volume is of a fixed size; @@ -85,8 +89,19 @@ level is 9. The number of dump records per volume. This option overrides the calculation of tape size based on length and density. +.It Cm a +.Dq auto-size . +Bypass all tape length considerations, and enforce writing +until an end-of-media indication is returned. This fits best +for most modern tape drives. Use of this option is particularly +recommended when appending to an existing tape, or using a tape +drive with hardware compression (where you can never be sure about +the compression ratio). .It Cm b Ar blocksize The number of kilobytes per dump record. +.It Cm c +Change the defaults for use with a cartridge tape drive, with a density +of 8000 bpi, and a length of 1700 feet. .It Cm h Ar level Honor the user .Dq nodump @@ -325,10 +340,12 @@ Each reel requires a new process, so parent processes for reels already written just hang around until the entire tape is written. .Pp -restore(8) is currently unable to restore dumps that were created -with a blocksize larger than 32 on some tape drives. This is likely -a bug in the tape driver. Workaround for safety reasons: -dump aborts with an error message when choosing a blocksize > 32. +Currently, +.Xr physio 9 +slices all requests into chunks of 64 KB. Therefore, it is +impossible to use a larger tape blocksize, so +.Nm dump +will prevent this from happening. .Pp .Nm Dump with the |