been changed and are in need of a transfer. Without this option, rsync
uses a "quick check" that (by default) checks if each file's size and time
of last modification match between the sender and receiver. This option
-changes this to compare a 128-bit MD4 checksum for each file that has a
+changes this to compare a 128-bit checksum for each file that has a
matching size. Generating the checksums means that both sides will expend
a lot of disk I/O reading all the data in the files in the transfer (and
this is prior to any reading that will be done to transfer changed files),
automatic after-the-transfer verification has nothing to do with this
option's before-the-transfer "Does this file need to be updated?" check.
+For protocol 30 and beyond (first supported in 3.0.0), the checksum used is
+MD5. For older protocols, the checksum used is MD4.
+
dit(bf(-a, --archive)) This is equivalent to bf(-rlptgoD). It is a quick
way of saying you want recursion and want to preserve almost
everything (with -H being a notable omission).
where the destination has a file, the transfer would occur regardless of
the timestamps.
+This option is a transfer rule, not an exclude, so it doesn't affect the
+data that goes into the file-lists, and thus it doesn't affect deletions.
+It just limits the files that the receiver requests to be transferred.
+
dit(bf(--inplace)) This option changes how rsync transfers a file when the
file's data needs to be updated: instead of the default method of creating
a new copy of the file and moving it into place when it is complete, rsync
combined with the bf(--ignore-existing) option, no files will be updated
(which can be useful if all you want to do is delete extraneous files).
+This option is a transfer rule, not an exclude, so it doesn't affect the
+data that goes into the file-lists, and thus it doesn't affect deletions.
+It just limits the files that the receiver requests to be transferred.
+
dit(bf(--ignore-existing)) This tells rsync to skip updating files that
already exist on the destination (this does em(not) ignore existing
directories, or nothing would get done). See also bf(--existing).
+This option is a transfer rule, not an exclude, so it doesn't affect the
+data that goes into the file-lists, and thus it doesn't affect deletions.
+It just limits the files that the receiver requests to be transferred.
+
This option can be useful for those doing backups using the bf(--link-dest)
option when they need to continue a backup run that got interrupted. Since
a bf(--link-dest) run is copied into a new directory hierarchy (when it is
suffixed with a string to indicate a size multiplier, and
may be a fractional value (e.g. "bf(--max-size=1.5m)").
+This option is a transfer rule, not an exclude, so it doesn't affect the
+data that goes into the file-lists, and thus it doesn't affect deletions.
+It just limits the files that the receiver requests to be transferred.
+
The suffixes are as follows: "K" (or "KiB") is a kibibyte (1024),
"M" (or "MiB") is a mebibyte (1024*1024), and "G" (or "GiB") is a
gibibyte (1024*1024*1024).
dit(bf(--min-size=SIZE)) This tells rsync to avoid transferring any
file that is smaller than the specified SIZE, which can help in not
transferring small, junk files.
-See the bf(--max-size) option for a description of SIZE.
+See the bf(--max-size) option for a description of SIZE and other information.
dit(bf(-B, --block-size=BLOCKSIZE)) This forces the block size used in
rsync's delta-transfer algorithm to a fixed value. It is normally selected based on
For a list of the possible escape characters, see the "log format" setting
in the rsyncd.conf manpage.
+The default FORMAT used if bf(--log-file) is specified and this option is not
+is '%i %n%L'.
+
dit(bf(--stats)) This tells rsync to print a verbose set of statistics
on the file transfer, allowing you to tell how effective rsync's delta-transfer
algorithm is for your data. This option is equivalent to bf(--info=stats2)
recursively scanning a hierarchy of files using include/exclude/filter
rules.
+Note that the use of transfer rules, such as the bf(--min-size) option, does
+not affect what goes into the file list, and thus does not leave directories
+empty, even if none of the files in a directory match the transfer rule.
+
Because the file-list is actually being pruned, this option also affects
what directories get deleted when a delete is active. However, keep in
mind that excluded files and directories can prevent existing items from
-being deleted (because an exclude hides source files and protects
-destination files).
+being deleted due to an exclude both hiding source files and protecting
+destination files. See the perishable filter-rule option for how to avoid
+this.
You can prevent the pruning of certain empty directories from the file-list
by using a global "protect" filter. For instance, this option would ensure
will have no effect. The bf(--version) output will tell you if this
is the case.
-dit(bf(--checksum-seed=NUM)) Set the MD4 checksum seed to the integer
+dit(bf(--checksum-seed=NUM)) Set the checksum seed to the integer
NUM. This 4 byte checksum seed is included in each block and file
-MD4 checksum calculation. By default the checksum seed is generated
+checksum calculation. By default the checksum seed is generated
by the server and defaults to the current code(time()). This option
is used to set a specific checksum seed, which is useful for
applications that want repeatable block and file checksums, or
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff