rsync(1) -aAXvH
a fast, versatile, remote (and local) file-copying tool
-a, --archive
       This is equivalent to -rlptgoD. It is a quick way  of  saying  you  want  recursion  and  want  to
       preserve  almost  everything  (with -H being a notable omission).  The only exception to the above
       equivalence is when --files-from is specified, in which case -r is not implied.

       Note that -a does not preserve hardlinks, because finding multiply-linked files is expensive.  You
       must separately specify -H.
-A, --acls
       This  option  causes  rsync to update the destination ACLs to be the same as the source ACLs.  The
       option also implies --perms.

       The source and destination systems must have compatible  ACL  entries  for  this  option  to  work
       properly.   See  the  --fake-super  option  for  a  way  to  backup  and restore ACLs that are not
-X, --xattrs
       This option causes rsync to update the destination extended attributes  to  be  the  same  as  the
       source ones.

       For  systems  that support extended-attribute namespaces, a copy being done by a super-user copies
       all namespaces except system.*.  A normal user only copies the user.* namespace.  To  be  able  to
       backup and restore non-user namespaces as a normal user, see the --fake-super option.

       Note  that this option does not copy rsyncs special xattr values (e.g. those used by --fake-super)
       unless you repeat the option (e.g. -XX).   This  "copy  all  xattrs"  mode  cannot  be  used  with
-v, --verbose
       This  option  increases  the amount of information you are given during the transfer.  By default,
       rsync works silently. A single -v will give you information about what files are being transferred
       and  a  brief summary at the end. Two -v options will give you information on what files are being
       skipped and slightly more information at the end. More than two -v options should only be used  if
       you are debugging rsync.

       Note that the names of the transferred files that are output are done using a default --out-format
       of "%n%L", which tells you just the name of the file and, if the item is a link, where it  points.
       At  the  single  -v  level  of  verbosity,  this  does not mention when a file gets its attributes
       changed.  If you ask for an itemized list  of  changed  attributes  (either  --itemize-changes  or
       adding  "%i"  to  the  --out-format  setting), the output (on the client) increases to mention all
       items that are changed in any way.  See the --out-format option for more details.
-H, --hard-links
       This  tells  rsync to look for hard-linked files in the source and link together the corresponding
       files on the destination.  Without this option, hard-linked files in the  source  are  treated  as
       though they were separate files.

       This  option does NOT necessarily ensure that the pattern of hard links on the destination exactly
       matches that on the source.  Cases in which the destination may  end  up  with  extra  hard  links
       include the following:

       o      If the destination contains extraneous hard-links (more linking than what is present in the
              source file list), the copying algorithm will not break them explicitly.  However,  if  one
              or  more  of  the paths have content differences, the normal file-update process will break
              those extra links (unless you are using the --inplace option).

       o      If you specify a --link-dest directory  that  contains  hard  links,  the  linking  of  the
              destination  files against the --link-dest files can cause some paths in the destination to
              become linked together due to the --link-dest associations.

       Note that rsync can only detect hard links between files that are inside  the  transfer  set.   If
       rsync  updates  a  file  that  has extra hard-link connections to files outside the transfer, that
       linkage will be broken.  If you are tempted to use the --inplace option to avoid this breakage, be
       very  careful  that  you  know  how  your  files are being updated so that you are certain that no
       unintended changes happen due to lingering hard links (and  see  the  --inplace  option  for  more

              If  incremental  recursion  is  active (see --recursive), rsync may transfer a missing hard-linked
              file before it finds that another link for that contents exists elsewhere in the hierarchy.   This
              does not affect the accuracy of the transfer (i.e. which files are hard-linked together), just its
              efficiency (i.e. copying the data for a new, early copy of a hard-linked file that could have been
              found  later in the transfer in another member of the hard-linked set of files).  One way to avoid
              this inefficiency is to disable incremental recursion using the --no-inc-recursive option.
source manpages: rsync