X-Git-Url: https://git.brokenzipper.com/gitweb?a=blobdiff_plain;f=doc%2Ftar.texi;h=c38e3e6a9ab211cb657de4ceac7d92591bd1ba1a;hb=87ac3207fbc12e3f186f338b36012d1ee40e90c1;hp=52b37258ebfa2cb72b7930c04fc23eb582ad927e;hpb=c8d4ceccc17ab5ce84e3c704569dbe22530a4aac;p=chaz%2Ftar diff --git a/doc/tar.texi b/doc/tar.texi index 52b3725..c38e3e6 100644 --- a/doc/tar.texi +++ b/doc/tar.texi @@ -109,6 +109,7 @@ Appendices * Changes:: * Configuring Help Summary:: +* Fixing Snapshot Files:: * Tar Internals:: * Genfile:: * Free Software Needs Free Documentation:: @@ -315,11 +316,16 @@ Date input formats Controlling the Archive Format -* Portability:: Making @command{tar} Archives More Portable * Compression:: Using Less Space through Compression * Attributes:: Handling File Attributes +* Portability:: Making @command{tar} Archives More Portable * cpio:: Comparison of @command{tar} and @command{cpio} +Using Less Space through Compression + +* gzip:: Creating and Reading Compressed Archives +* sparse:: Archiving Sparse Files + Making @command{tar} Archives More Portable * Portable Names:: Portable Names @@ -342,11 +348,6 @@ How to Extract GNU-Specific Data Using Other @command{tar} Implementations * Split Recovery:: Members Split Between Volumes * Sparse Recovery:: Sparse Members -Using Less Space through Compression - -* gzip:: Creating and Reading Compressed Archives -* sparse:: Archiving Sparse Files - Tapes and Other Archive Media * Device:: Device selection and switching @@ -5406,6 +5407,7 @@ unreliable if you modify a file's time stamps during dumping (e.g., with the @option{--atime-preserve=replace} option), or if you set the clock backwards. +@cindex Device numbers, using in incremental backups Metadata stored in snapshot files include device numbers, which, obviously is supposed to be a non-volatile value. However, it turns out that NFS devices have undependable values when an automounter @@ -5416,6 +5418,11 @@ is to considers all NFS devices as being equal when it comes to comparing directories; this is fairly gross, but there does not seem to be a better way to go. +If you are using the @i{Linux} kernel, the device numbers can also +change when upgrading to some newer versions of the kernel. This can +cause the next backup to be full backup on the affected filesystems. +@xref{Fixing Snapshot Files}, for the information on how to handle this case. + Note that incremental archives use @command{tar} extensions and may not be readable by non-@acronym{GNU} versions of the @command{tar} program. @@ -10272,7 +10279,7 @@ echo $@{name:-$TAR_ARCHIVE@}-$TAR_VOLUME >&$TAR_FD @end group @end smallexample -The same script cant be used while listing, comparing or extracting +The same script can be used while listing, comparing or extracting from the created archive. For example: @smallexample @@ -10914,6 +10921,10 @@ output. Default is 12. Right margin of the text output. Used for wrapping. @end deftypevr +@node Fixing Snapshot Files +@appendix Fixing Snapshot Files +@include tar-snapshot-edit.texi + @node Tar Internals @appendix Tar Internals @include intern.texi