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rsync

useful command line options

options affecting the transfer:

-S, --sparse -A, --acls -X, --xattrs -H, --hard-links -a, --archive -P --partial --progress --numeric-ids

rsync -avhSAXPH src dest/
rsync -avhSAXPH --numeric-ids --delete --exclude=/proc --exclude=/sys --exclude=/dev --exclude=/tmp --exclude=/run src dest/

Options affecting the output

-v, --verbose -h, --human-readable

Other flags to consider

-z option adds compression.

for fat32 file32 systems

rsync -rtvhP --modify-window=1 --delete-after ...

If you don't like that all of your files show up as executables, you could remount the file system with different options.

for wizbackups

Use the H flag to preserve hardlinks for wizbackup dirs, since files that havent changed between backups are hardlinked to save space. This flag slows down overall transfer (not sure exactly how much), but it's probably not worth using otherwise.

caveats

be careful about trailing slashes on the source directory. if you include a slash, the contents of the directory will be synced into the destination, rather than a directory in the destination directory.

also be careful about syning a home dir from a remote server to your local home, or vice versa. this will likely screw up your ssh keys and other dot files / directories.

Note the leading / characters in the --exclude= parameters. These are necessary so you don't exclude paths like /foo/tmp.

Overall progress

Here is an example of using df to track progress of a long running transfer. For a long transfers, the v and P flag mostly just waste cpu cycles and I (Ian) don't use them.

replace /mnt/monolith below

mnt=/mnt/monolith
m() { df -BM $mnt | tail -n1 | awk '{print $3}'| sed 's/[^0-9]//g'; }
size-watch() {
  old=$(m)
  while true; do
    sleep 600
    new=$(m)
    printf "%s %'d MB/min in last 10 minutes\n" "$(date)" $(( (new - old) / 10))
    old=$new
  done
}
size-watch