--- a/dump/dump.h
+++ b/dump/dump.h
@@ -223,8 +223,8 @@ extern int	nddates;		/* number of record
 extern int	ddates_in;		/* we have read the increment file */
 extern struct	dumpdates **ddatev;	/* the arrayfied version */
 void	initdumptimes (int);
-void	getdumptime (int);
-void	putdumptime (void);
+void	getdumptime (int, const char *);
+void	putdumptime (const char *);
 #define	ITITERATE(i, ddp) \
 	for (ddp = ddatev[i = 0]; i < nddates; ddp = ddatev[++i])
 
--- a/dump/itime.c
+++ b/dump/itime.c
@@ -147,7 +147,7 @@ readdumptimes(FILE *df)
 }
 
 void
-getdumptime(int createdumpdates)
+getdumptime(int createdumpdates, const char * disk)
 {
 	struct dumpdates *ddp;
 	int i;
@@ -185,7 +185,7 @@ getdumptime(int createdumpdates)
 }
 
 void
-putdumptime(void)
+putdumptime(const char * disk)
 {
 	FILE *df;
 	struct dumpdates *dtwalk;
--- a/dump/main.c
+++ b/dump/main.c
@@ -664,7 +664,7 @@ main(int argc, char *argv[])
 	spcl.c_level = atoi(level);
 	spcl.c_type = TS_TAPE;
 	if (!Tflag)
-		getdumptime(uflag);		/* dumpdates snarfed */
+     getdumptime(uflag,diskparam);		/* dumpdates snarfed */
 
 	if (spcl.c_ddate == 0 && spcl.c_level) {
 		msg("WARNING: There is no inferior level dump on this filesystem\n");
@@ -1029,7 +1029,7 @@ main(int argc, char *argv[])
 		    tend_writing - tstart_writing,
 		    spcl.c_tapea / (tend_writing - tstart_writing));
 
-	putdumptime();
+	putdumptime(diskparam);
 	msg("Date of this level %s dump: %s", level,
 		spcl.c_date == 0 ? "the epoch\n" : ctime4(&spcl.c_date));
 	msg("Date this dump completed:  %s", ctime(&tnow));
--- a/dump/dump.8.in
+++ b/dump/dump.8.in
@@ -1,5 +1,5 @@
 .\" Copyright (c) 1980, 1991, 1993
-.\"	 Regents of the University of California.
+.\"  Regents of the University of California.
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
@@ -30,7 +30,7 @@
 .SH NAME
 dump \- ext2/3/4 filesystem backup
 .SH SYNOPSIS
-.B dump 
+.B dump
 [\fB\-\fIlevel#\fR]
 [\fB\-ackMnqSuv]
 [\fB\-A \fIfile\fR]
@@ -53,32 +53,44 @@ dump \- ext2/3/4 filesystem backup
 [\fB\-z\fIcompression level\fR]
 .I files-to-dump
 .PP
-.B dump 
+.B dump
 [\fB\-W \fR| \fB\-w\fR]
 .SH DESCRIPTION
 .B Dump
 examines files on an ext2/3/4 filesystem and determines which files need to be
 backed up. These files are copied to the given disk, tape or other storage
 medium for safe keeping (see the
-.B \-f 
-option below for doing remote backups). A dump that is larger than the output 
+.B \-f
+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.
 .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; the actual size is 
+cartridge tape drives), each volume is of a fixed size; the actual size is
 determined by specifying cartridge media, or via the tape size, density and/or
 block count options below. By default, the same output file name is used for
 each volume after prompting the operator to change media.
 .PP
 .I files-to-dump
-is either a mountpoint 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:
+can be a filesystem identifier or a list of files and directories to be backed up.
+.PP
+A filesystem can be identified by its device path (e.g.
+.IR "/dev/sde2" ),
+by its mountpoint if the filesystem is currently mounted (e.g.
+.IR /var ),
+or by its label or uuid property if the block device is known to
+.BR blkid (8)
+(e.g.
+.I LABEL=foobar
+or
+.IR UUID=a0f155-... ).
+.PP
+If
+.I files-to-dump
+is a list of files and directories, then certain restrictions apply:
 .B \-u
 is not allowed, the only dump level that is supported is
-.B 0 
+.B 0
 and all the files and directories must reside on the same filesystem.
 .SH OPTIONS
 The following options are supported by
@@ -92,21 +104,21 @@ guarantees the entire file system is cop
 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 
+copy all files new or modified since the last dump of a lower level. The
 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 
+.BI \-a
+\*(lqauto-size\*(rq. Bypass all tape length calculations, and write until an
 end-of-media indication is returned.  This works best for most modern tape
 drives, and is the default. Use of this option is particularly recommended when
-appending to an existing tape, or using a tape drive with hardware compression 
+appending to an existing tape, or using a tape drive with hardware compression
 (where you can never be sure about the compression ratio).
 .TP
 .BI \-A " archive_file"
 Archive a dump table-of-contents in the specified
 .I archive_file
-to be used by 
+to be used by
 .BR restore (8)
 to determine whether a file is in the dump file that is being restored.
 .TP
@@ -117,7 +129,7 @@ unless the
 option has been used to specify a tape density of 6250BPI or more,
 in which case the default blocksize is 32. Th maximal value is 1024.
 Note however that, since the IO system slices all requests into chunks
-of 
+of
 .B MAXBSIZE
 (which can be as low as 64kB), you can experience problems with
 .BR dump (8)
@@ -130,8 +142,8 @@ The number of 1 kB blocks per volume. No
 .B dump
 can detect end-of-media. When the specified size is reached,
 .B dump
-waits for you to change the volume.  This option overrides the calculation of 
-tape size based on length and density. If compression is on this limits the 
+waits for you to change the volume.  This option overrides the calculation of
+tape size based on length and density. If compression is on this limits the
 size of the compressed output per volume.  Multiple values may be given
 as a single argument separated by commas.  Each value will be used for one
 dump volume in the order listed; if
@@ -154,12 +166,12 @@ The default is 1600BPI. Specifying a tap
 detection.
 .TP
 .BI \-D " file"
-Set the path name of the file storing the information about the previous 
+Set the path name of the file storing the information about the previous
 full and incremental dumps. The default location is
 .IR __DUMPDATES__ .
 .TP
 .BI \-e " inodes"
-Exclude 
+Exclude
 .I inodes
 from the dump. The
 .I inodes
@@ -170,7 +182,7 @@ to find the inode number for a file or d
 .BI \-E " file"
 Read list of inodes to be excluded from the dump from the text file
 .IR file .
-The file 
+The file
 .I file
 should be an ordinary file containing inode numbers separated by newlines.
 .TP
@@ -193,7 +205,7 @@ media changes. If the name of the file i
 or
 .I user@host:file
 .B dump
-writes to the named file on the remote host (which should already 
+writes to the named file on the remote host (which should already
 exist, dump doesn't create a new remote file) using
 .BR rmt (8).
 The default path name of the remote
@@ -204,13 +216,13 @@ this can be overridden by the environmen
 .BR RMT .
 .TP
 .BI \-F " script"
-Run script at the end of each tape (except for the last one). 
+Run script at the end of each tape (except for the last one).
 The device name and the current volume number are passed on the
-command line. The script must return 0 if 
+command line. The script must return 0 if
 .B dump
-should continue without asking the user to change the tape, 1 if 
+should continue without asking the user to change the tape, 1 if
 .B dump
-should continue but ask the user to change the tape. Any other exit code will 
+should continue but ask the user to change the tape. Any other exit code will
 cause
 .B dump
 to abort. For security reasons,
@@ -231,11 +243,11 @@ full backups retain them.
 .BI \-I " nr errors"
 By default,
 .B dump
-will ignore the first 32 read errors on the file system before asking for 
-operator intervention. You can change this using this flag to any value. This 
+will ignore the first 32 read errors on the file system before asking for
+operator intervention. You can change this using this flag to any value. This
 is useful when running
 .B dump
-on an active filesystem where read errors simply indicate an inconsistency 
+on an active filesystem where read errors simply indicate an inconsistency
 between the mapping and dumping passes.
 .IP
 A value of 0 means that all read errors will be ignored.
@@ -244,12 +256,12 @@ A value of 0 means that all read errors
 Compress every block to be written on the tape using bzlib library. This option
 will work only when dumping to a file or pipe or, when dumping to a tape drive,
 if the tape drive is capable of writing variable length blocks. You will need
-at least the 0.4b24 version of 
+at least the 0.4b24 version of
 .B restore
 in order to extract compressed tapes. Tapes written using compression will not
-be compatible with the BSD tape format. The (optional) parameter specifies the 
+be compatible with the BSD tape format. The (optional) parameter specifies the
 compression level bzlib will use. The default compression level is 2. If the
-optional parameter is specified, there should be no white space between the 
+optional parameter is specified, there should be no white space between the
 option letter and the parameter.
 .TP
 .BI \-k
@@ -265,20 +277,20 @@ is placed into the dump header, where to
 .BR restore (8)
 and
 .BR file (8)
-can access it. Note that this label is limited to be at most 
+can access it. Note that this label is limited to be at most
 .B LBLSIZE
 (currently 16) characters, which must include the terminating \e0.
 .TP
 .BI \-m
 If this flag is specified,
 .B dump
-will optimise the output for inodes having been changed but not modified since 
+will optimise the output for inodes having been changed but not modified since
 the last dump ('changed' and 'modified' have the meaning defined in
 .BR stat (2)
 ). For those inodes,
 .B dump
-will save only the metadata, instead of saving the entire inode contents. 
-Inodes which are either directories or have been modified since the last dump 
+will save only the metadata, instead of saving the entire inode contents.
+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
@@ -293,12 +305,12 @@ BSD tape format or older versions of
 .B restore.
 .TP
 .BI \-M
-Enable the multi-volume feature. The name specified with 
-.B f 
-is treated as a prefix and 
+Enable the multi-volume feature. The name specified with
+.B f
+is treated as a prefix and
 .B dump
 writes in sequence to
-.I <prefix>001, <prefix>002 
+.I <prefix>001, <prefix>002
 etc. This can be useful when dumping to files on an ext2/3/4 partition, in order to
 bypass the 2GB file size limitation.
 .TP
@@ -317,31 +329,31 @@ abort immediately whenever operator atte
 case of write errors, tape changes etc.
 .TP
 .BI \-Q " file"
-Enable the Quick File Access support. Tape positions for each inode are stored 
+Enable the Quick File Access support. Tape positions for each inode are stored
 into the file
 .I file
-which is used by 
+which is used by
 .B restore
-(if called with parameter 
+(if called with parameter
 .B \-Q
-and the filename) to directly position the tape at the file 
-.B restore 
+and the filename) to directly position the tape at the file
+.B restore
 is currently working on. This saves hours when restoring single files from
 large backups, saves the tapes and the drive's head.
 .IP
-It is recommended to set up the st driver to return logical tape positions 
-rather than physical before calling 
-.B dump/restore 
-with parameter 
+It is recommended to set up the st driver to return logical tape positions
+rather than physical before calling
+.B dump/restore
+with parameter
 .BR \-Q .
-Since not all tape devices support physical tape positions those tape devices 
-return an error during 
+Since not all tape devices support physical tape positions those tape devices
+return an error during
 .B dump/restore
-when the st driver is set to the default physical setting.  Please see the 
+when the st driver is set to the default physical setting.  Please see the
 .BR st (4)
-man page, option 
+man page, option
 .B MTSETDRVBUFFER
-, or the 
+, or the
 .BR mt (1)
 man page, on how to set the driver to return logical tape positions.
 .IP
@@ -350,21 +362,21 @@ Before calling
 with parameter
 .BR \-Q ,
 always make sure the st driver is set to return the same type of tape position
-used during the call to 
+used during the call to
 .BR dump .
-Otherwise 
+Otherwise
 .B restore
 may be confused.
 .IP
-This option can be used when dumping to local tapes (see above) or to local 
+This option can be used when dumping to local tapes (see above) or to local
 files.
 .TP
 .BI \-s " feet"
 Attempt to calculate the amount of tape needed at a particular density. If this
 amount is exceeded,
 .B dump
-prompts for a new tape. It is recommended to be a bit conservative on this 
-option. The default tape length is 2300 feet. Specifying the tape size 
+prompts for a new tape. It is recommended to be a bit conservative on this
+option. The default tape length is 2300 feet. Specifying the tape size
 overrides end-of-media detection.
 .TP
 .BI \-S
@@ -374,7 +386,7 @@ take. This is useful with incremental du
 media will be needed.
 .TP
 .BI \-T " date"
-Use the specified date as the starting time for the dump instead of the time 
+Use the specified date as the starting time for the dump instead of the time
 determined from looking in
 .I __DUMPDATES__ .
 The format of
@@ -389,7 +401,7 @@ daylight savings time (if applicable to
 when daylight savings time is in effect will be different than offsets
 when daylight savings time is not in effect. For backward
 compatibility, if no timezone is specified, a local time is assumed.
-This option is useful for automated dump scripts that wish to dump over a 
+This option is useful for automated dump scripts that wish to dump over a
 specific period of time. The
 .B \-T
 option is mutually exclusive from the
@@ -401,15 +413,21 @@ Update the file
 .I __DUMPDATES__
 after a successful dump. The format of
 .I __DUMPDATES__
-is readable by people, consisting of one free format record per line:
-filesystem name, increment level and
+is human-readable, with one record per line. Each line holds, separated by spaces,
+a filesystem identifier, dump increment level and dump date in
 .BR ctime (3)
-format dump date followed by a rfc822 timezone specification (see the
-.B \-u
-option for details). If no timezone offset is specified, times are interpreted 
-as local. Whenever the file is written, all dates in the file are converted 
-to the local time zone, without changing the UTC times. There
-may be only one entry per filesystem at each level. The file
+format followed by a rfc822 timezone specification (see the
+.B \-T
+option for details). If no timezone offset is specified, times are interpreted
+as local. Whenever the file is written, all dates in the file are converted
+to the local time zone, without changing the UTC times.
+.IP
+The filesystem identifier is exactly as given on the command line, e.g.
+.B UUID=a0f155-...
+or
+.BR /dev/sde2 .
+This is for incremental dumps of filesystems on removable media or other
+situations where the device path changes over time. There may be at most one entry per filesystem for each increment level. The file
 .I __DUMPDATES__
 may be edited to change any of the fields, if necessary.
 .TP
@@ -437,13 +455,13 @@ and recognized file systems in
 .I /etc/mtab
 and
 .IR /etc/fstab .
-the most recent dump date and level, and highlights those that should be 
+the most recent dump date and level, and highlights those that should be
 dumped. If the
 .B \-W
 option is set, all other options are ignored, and
 .B dump
 exits immediately.
-.TP 
+.TP
 .BI \-w
 Is like
 .BR \-W ,
@@ -466,18 +484,18 @@ be compatible with the BSD tape format.
 .BI \-z "compression level"
 Compress every block to be written on the tape using zlib library. This option
 will work only when dumping to a file or pipe or, when dumping to a tape drive,
-if the tape drive is capable of writing variable length blocks. You will need 
+if the tape drive is capable of writing variable length blocks. You will need
 at least the 0.4b22 version of
 .B restore
 in order to extract compressed tapes. Tapes written using compression will not
 be compatible with the BSD tape format. The (optional) parameter specifies the
 compression level zlib will use. The default compression level is 2. If the
-optional parameter is specified, there should be no white space between the 
+optional parameter is specified, there should be no white space between the
 option letter and the parameter.
 .PP
 .B Dump
 requires operator intervention on these conditions: end of tape, end of dump,
-tape write error, tape open error or disk read error (if there is more than a 
+tape write error, tape open error or disk read error (if there is more than a
 threshold of nr errors). In addition to alerting all operators implied by the
 .B \-n
 key,
@@ -499,7 +517,7 @@ will, with operator permission, restart
 old tape has been rewound and removed, and a new tape has been mounted.
 .PP
 .B Dump
-tells the operator what is going on at periodic intervals, including usually 
+tells the operator what is going on at periodic intervals, including usually
 low estimates of the number of blocks to write, the number of tapes it will
 take, the time to completion, and the time to the tape change. The output is
 verbose, so that others know that the terminal controlling
@@ -507,7 +525,7 @@ verbose, so that others know that the te
 is busy, and will be for some time.
 .PP
 In the event of a catastrophic disk event, the time required to restore all the
-necessary backup tapes or files to disk can be kept to a minimum by staggering 
+necessary backup tapes or files to disk can be kept to a minimum by staggering
 the incremental dumps. An efficient method of staggering incremental dumps to
 minimize the number of tapes follows:
 .IP \(em
@@ -527,7 +545,7 @@ with this sequence of dump levels:
 .IP
 For the daily dumps, it should be possible to use a fixed number of tapes for
 each day, used on a weekly basis. Each week, a level 1 dump is taken, and the
-daily Hanoi sequence repeats beginning with 3. For weekly dumps, another fixed 
+daily Hanoi sequence repeats beginning with 3. For weekly dumps, another fixed
 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
@@ -542,10 +560,10 @@ information).
 (The 4.3BSD option syntax is implemented for backward compatibility but is not
 documented here.)
 .SH ENVIRONMENT
-.TP 
+.TP
 .B TAPE
-If no 
-.B \-f 
+If no
+.B \-f
 option was specified,
 .B dump
 will use the device specified via
@@ -569,7 +587,7 @@ program.
 .B Dump
 uses the contents of this variable to determine the name of the remote shell
 command to use when doing remote backups (rsh, ssh etc.). If this variable is
-not set, 
+not set,
 .BR rcmd (3)
 will be used, but only root will be able to do remote backups.
 .SH FILES
@@ -612,7 +630,7 @@ code of 1; abnormal termination is indic
 It might be considered a bug that this version of dump can only handle ext2/3/4
 filesystems.  Specifically, it does not work with FAT filesystems.
 .PP
-Fewer than 32 read errors (change this with 
+Fewer than 32 read errors (change this with
 .BR \-I )
 on the filesystem are ignored. If noticing read errors is important, the output
 from dump can be parsed to look for lines that contain the text 'read error'.
@@ -621,7 +639,7 @@ When a read error occurs,
 .B dump
 prints out the corresponding physical disk block and sector number and the
 ext2/3/4 logical block number. It doesn't print out the corresponding file name or
-even the inode number. The user has to use 
+even the inode number. The user has to use
 .BR debugfs (8),
 commands
 .B ncheck
@@ -629,7 +647,7 @@ and
 .B icheck
 to translate the
 .B ext2blk
-number printed out by 
+number printed out by
 .B dump
 into an inode number, then into a file name.
 .PP
@@ -641,21 +659,21 @@ The estimated number of tapes is not cor
 It would be nice if
 .B dump
 knew about the dump sequence, kept track of the tapes scribbled on, told the
-operator which tape to mount when, and provided more assistance for the 
+operator which tape to mount when, and provided more assistance for the
 operator running
 .BR restore .
 .PP
 .B Dump
 cannot do remote backups without being run as root, due to its security history.
 Presently, it works if you set it setuid (like it used to be), but this might
-constitute a security risk. Note that you can set 
+constitute a security risk. Note that you can set
 .B RSH
 to use a remote shell program instead.
 .SH AUTHOR
-The 
+The
 .B dump/restore
-backup suite was ported to Linux's Second Extended File System by Remy Card 
-<card@Linux.EU.Org>. He maintained the initial versions of 
+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).
 .PP
