Linux – rsync invocation to replace symlinks pointing to source

I would use rsync as it means that if it is interrupted for any reason, then you can restart it easily with very little cost. And being rsync, it can even restart part way through a large file. As others mention, it can exclude files easily. The simplest way to preserve most things is to use the -a flag – ‘archive.’ So:

rsync -a source dest

Although UID/GID and symlinks are preserved by -a (see -lpgo), your question implies you might want a full copy of the filesystem information; and -a doesn't include hard-links, extended attributes, or ACLs (on Linux) or the above nor resource forks (on OS X.) Thus, for a robust copy of a filesystem, you'll need to include those flags:

rsync -aHAX source dest # Linux
rsync -aHE source dest  # OS X

The default cp will start again, though the -u flag will "copy only when the SOURCE file is newer than the destination file or when the destination file is missing". And the -a (archive) flag will be recursive, not recopy files if you have to restart and preserve permissions. So:

cp -au source dest

It's all of these:

-r, --recursive recurse into directories

-l, --links copy symlinks as symlinks

-p, --perms preserve permissions

-t, --times preserve modification times

-g, --group preserve group

-o, --owner preserve owner (super-user only)

-D same as --devices --specials

--devices preserve device files (super-user only)

--specials preserve special files

It excludes:

-H, --hard-links preserve hard links

-A, --acls preserve ACLs (implies -p)

-X, --xattrs preserve extended attributes

It's perfect for backups. My "default" set of switches is -avzP - archive mode, be verbose, use compression, preserve partial files, display progress.

Note: Invariably when the descriptions say "preserve", it means make the destination be like the source.