...
Rsync
...
is
...
a
...
data
...
transfer
...
tool.
...
To
...
use
...
rsync
...
you
...
will
...
be
...
provide
...
it
...
with
...
a
...
source,
...
and
...
a
...
destination.
...
For
...
each
...
file
...
in
...
the
...
source,
...
rsync
...
will
...
first
...
look
...
to
...
see
...
if
...
the
...
file
...
exists
...
in
...
the
...
target.
...
If
...
not,
...
then
...
rsync
...
will
...
transfer
...
a
...
copy
...
of
...
the
...
file
...
to
...
the
...
target.
...
If
...
file
...
does
...
exist
...
on
...
the
...
target,
...
then
...
rsync
...
confirms
...
that
...
the
...
files
...
are
...
the
...
same.
...
If
...
not,
...
then
...
it
...
determines
...
the
...
smallest
...
amount
...
of
...
data
...
that
...
needs
...
to
...
be
...
transferred
...
to
...
make
...
the
...
target
...
file
...
look
...
like
...
the
...
source
...
file.
...
This
...
makes
...
rsync
...
ideal
...
for
...
mirroring
...
sets
...
of
...
files.
...
Because
...
rsync
...
ignores
...
files
...
that
...
are
...
up
...
to
...
date
...
it's
...
also
...
useful
...
for
...
resuming
...
a
...
transfer
...
that
...
might
...
have
...
gotten
...
interrupted.
...
However,
...
this
...
powerful
...
piece
...
of
...
software
...
can
...
easily
...
be
...
used
...
to
...
create
...
a
...
mess,
...
or
...
damage
...
files.
...
If
...
you
...
wish
...
to
...
use
...
rsync
...
you
...
should
...
carefully
...
read
...
through
...
this
...
document
...
to
...
make
...
sure
...
you
...
understand
...
its
...
proper
...
use.
...
It
...
does
...
also
...
require
...
a
...
bit
...
more
...
familiarity
...
with
...
how
...
files
...
are
...
stored,
...
and
...
accessed
...
in
...
UNIX.
...
If
...
you
...
are
...
still
...
not
...
comfortable
...
with
...
this,
...
you
...
should
...
visit
...
our
...
...
...
...
which
...
has
...
some
...
references
...
for
...
learning
...
to
...
work
...
with
...
UNIX.
...
You
...
might
...
also
...
refer
...
to
...
our
...
...
which
...
defines
...
some
...
commonly
...
used
...
terms.
...
UNIX
...
users
...
(and
...
Mac
...
by
...
use
...
of
...
Terminal.app)
...
can
...
use
...
rsync
...
by
...
typing
...
| Code Block |
|---|
rsync opts src tgt
{code}
|
src
...
and
...
tgt
...
are
...
the
...
locations
...
that
...
you
...
want
...
to
...
keep
...
synced.
...
The
...
rule
...
is
...
that
...
tgt
...
will
...
be
...
made
...
to
...
look
...
like
...
src.
...
There
...
are
...
several
...
options.
...
First,
...
you
...
can
...
just
...
use
...
short
...
names.
...
For
...
example,
...
rsync
...
a
...
b
...
will
...
sync
...
object
...
a
...
to
...
object
...
b
...
where
...
both
...
a
...
and
...
b
...
are
...
in
...
your
...
current
...
working
...
directory.
...
By
...
object,
...
it
...
is
...
meant
...
either
...
a
...
file
...
or
...
a
...
directory.
...
For
...
example,
...
rsync
...
a
...
b
...
will
...
sync
...
a
...
to
...
b.
...
If
...
a,
...
and
...
b
...
are
...
both
...
files,
...
then
...
b
...
is
...
updated
...
to
...
look
...
like
...
a.
...
If
...
b
...
is
...
a
...
directory,
...
then
...
b/a
...
is
...
updated
...
to
...
look
...
like
...
a.
...
Keep
...
in
...
mind
...
that
...
"update"
...
means
...
"created"
...
if
...
it
...
doesn't
...
exist.
...
If
...
a
...
is
...
a
...
directory,
...
then
...
rsync
...
will
...
fail
...
because,
...
by
...
default,
...
rsync
...
will
...
not
...
transfer
...
directories.
...
You
...
can
...
get
...
around
...
this
...
by
...
using
...
the
...
-a
...
option.
...
In
...
other
...
words,
...
rsync
...
-a
...
a
...
b
...
will
...
transfer
...
the
...
directory
...
a
...
to
...
become
...
b.
...
Typically,
...
you
...
will
...
almost
...
always
...
be
...
using
...
-a,
...
since
...
it
...
sets
...
a
...
number
...
of
...
other
...
options
...
which
...
are
...
used
...
to
...
help
...
rsync
...
mirror
...
sets
...
of
...
files
...
between
...
two
...
locations.
...
With
...
this
...
use
...
of
...
rsync
...
b/a
...
is
...
created
...
or
...
updated.
...
If
...
you
...
use
...
a/
...
as
...
a
...
source,
...
then
...
the
...
contents
...
of
...
a
...
are
...
placed
...
in
...
b.
...
You
...
can
...
also
...
use
...
the
...
trailing
...
slash
...
with
...
a
...
target.
...
For
...
example,
...
if
...
a
...
is
...
a
...
file,
...
and
...
you
...
run
...
rsync
...
-a
...
a
...
b
...
then
...
either
...
b
...
(if
...
it
...
is
...
a
...
file),
...
or
...
b/a
...
(if
...
it
...
is
...
a
...
directory)
...
is
...
updated.
...
In
...
the
...
case
...
that
...
you
...
want
...
to
...
guard
...
against
...
typos
...
overwriting
...
a
...
file,
...
you
...
can
...
use
...
b/.
...
Then
...
if
...
what
...
you
...
type
...
is
...
not
...
a
...
directory,
...
rsync
...
will
...
refuse
...
to
...
transfer
...
the
...
file.
...
To
...
sum
...
up
...
object
...
meaning
...
a
...
b
...
sync
...
object
...
(file
...
or
...
directory)
...
a
...
to
...
(file
...
or
...
directory
...
b)
...
a/
...
b
...
sync
...
contents
...
of
...
directory
...
a
...
to
...
b
...
a b/
...
sync
...
a
...
to
...
directory
...
b
...
a/
...
b/
...
sync
...
directory
...
a/
...
to
...
b/
...
Syncing
...
to
...
a
...
Remote/Host
...
Until
...
now
...
we've
...
just
...
assumed
...
that
...
we
...
are
...
syncing
...
files
...
in
...
the
...
same
...
directory.
...
However,
...
rsync
...
will
...
also
...
sync
...
files
...
between
...
directories.
...
For
...
example,
...
if
...
you
...
have
...
modified
...
files
...
in
...
your
...
home
...
directory,
...
you
...
might
...
want
...
to
...
make
...
sure
...
the
...
changed
...
files
...
are
...
in
...
your
...
personal
...
directory
...
in
...
your
...
lab
...
folder.
...
In
...
this
...
case
...
you
...
could
...
run,
...
rsync
...
-a
...
a
...
/share/FooLab/bar1234/ProjectFiles
...
which
...
creates
...
or
...
updates
...
/share/FooLab/bar1234/ProjectFiles/a.
...
You
...
can
...
reverse
...
this
...
off
...
course.
...
Finally,
...
rsync
...
allows
...
either
...
the
...
source
...
or
...
the
...
target
...
on
...
a
...
remote
...
host.
...
This
...
allows
...
you
...
to
...
sync
...
files
...
to
...
a
...
remote
...
host,
...
using
...
the
...
syntax
...
rsync
...
-a
...
a
...
remote_host:dir
...
which
...
places
...
the
...
object
...
a
...
in
...
the
...
directory
...
dir
...
on
...
the
...
the
...
host
...
remote_host.
...
If
...
dir
...
is
...
a
...
full
...
path,
...
then
...
that
...
is
...
where
...
the
...
syncing
...
is
...
done.
...
If
...
it
...
not,
...
then
...
the
...
syncing
...
is
...
done
...
in
...
~/dir
...
where
...
~
...
is
...
the
...
directory
...
your
...
are
...
logged
...
in
...
to
...
when
...
you
...
access
...
the
...
remote
...
system
...
using
...
ssh.
...
If
...
you
...
don't
...
provide
...
a
...
directory
...
at
...
all,
...
then
...
~/a
...
is
...
synced.
...
Other Options
Besides -a
...
to
...
set
...
up
...
mirroring,
...
rsync
...
comes
...
with
...
a
...
number
...
of
...
other
...
options.
...
For
...
example,
...
you
...
can
...
use
...
--verbose
...
to
...
see
...
the
...
list
...
of
...
files
...
that
...
are
...
being
...
transferred.
...
Over
...
time
...
you
...
may
...
find
...
that
...
there
...
are
...
files
...
that
...
are
...
being
...
transferred
...
that
...
you
...
don't
...
care
...
about.
...
For
...
example,
...
you
...
might
...
be
...
using
...
rsync
...
to
...
copy
...
the
...
contents
...
of
...
your
...
home
...
directory
...
over.
...
In
...
this
...
case,
...
you
...
may
...
notice
...
files
...
being
...
synced
...
over
...
that
...
you
...
don't
...
care
...
about.
...
For
...
example,
...
I
...
notice
...
that
...
when
...
I
...
rsync
...
my
...
home
...
directory,
...
cache
...
files
...
created
...
by
...
pages
...
created
...
by
...
firefox.
...
In
...
this
...
case
...
using
...
--exclude=.mozilla/firefox/eog3nqtx.default/Cache
...
ensures
...
that
...
these
...
files
...
files
...
don't
...
care
...
copied
...
over.
...
You
...
can
...
use
...
--exclude
...
multiple
...
times,
...
and
...
if
...
you
...
have
...
enough
...
of
...
them,
...
you
...
can
...
put
...
them
...
into
...
a
...
file;
...
then,
...
you
...
can
...
use
...
--exclude-from=FILE
...
to
...
tell
...
rysnc
...
to
...
use
...
the
...
named
...
file
...
as
...
a
...
list
...
of
...
patterns
...
to
...
exclude.
...
You
...
may
...
also
...
want
...
to
...
use
...
--delete
...
which
...
tells
...
rsync
...
to
...
remove
...
deleted
...
files
...
in
...
the
...
target
...
since
...
by
...
default
...
it
...
doesn't
...
do
...
this.
...
Another
...
way
...
to
...
avoid
...
rsyncing
...
lots
...
of
...
junk
...
is
...
to
...
only
...
rsync
...
the
...
things
...
you
...
are
...
interested
...
in.
...
You
...
can
...
either
...
list
...
of
...
objects
...
can
...
be
...
used
...
in
...
--include-from=FILE,
...
or
...
--files-from=FILE
...
where
...
FILE
...
is
...
again
...
the
...
file
...
name.
...
The
...
difference
...
is
...
that
...
the
...
include
...
file
...
used
...
in
...
include-from
...
can
...
have
...
wildcards
...
(as
...
can
...
exclude-from).
...
For
...
more
...
information
...
about
...
wildcards,
...
run
...
man
...
rsync
...
and
...
read
...
about
...
it.
...
Also,
...
--dry-run,
...
--list-only,
...
and
...
--itemize-changes
...
are
...
good
...
ways
...
to
...
see
...
what
...
rsync
...
is
...
doing,
...
or
...
to
...
test
...
what
...
it
...
might
...
do.
...
Finally,
...
sometimes
...
on
...
remote
...
systems
Rsync as a Backup Tool
This section will provide a mechanism for CCBB users to easily back their Mac or Linux laptops up. First, prep by logging into files.ccbb.utexas.edu
...
using
...
ssh,
...
and
...
then
...
changing
...
to
...
your
...
lab's
...
bulk
...
share.
...
Please
...
do
...
not
...
use
...
home
...
directories
...
for
...
this,
...
as
...
we
...
do
...
not
...
have
...
space
...
to
...
do
...
this.
...
Anybody
...
that
...
we
...
have
...
obligations
...
to
...
backup
...
will
...
also
...
be
...
a
...
member
...
of
...
a
...
lab
...
with
...
a
...
lab
...
share.
...
Within
...
your
...
lab
...
share
...
you
...
should
...
have
...
a
...
personal
...
folder
...
which
...
only
...
you,
...
and
...
your
...
lab
...
head
...
can
...
access.
...
Make
...
a
...
unique
...
for
...
your
...
backup
...
(say
...
LAPTOP).
...
Next
...
on
...
your
...
system
...
run
...
the
...
commands
...
mkdir
...
~/bin
...
mkidr
...
~/.ccbb-rsync-backup
...
Go
...
into
...
the
...
directory
...
~/bin,
...
and
...
use
...
an
...
editor
...
to
...
create
...
file
...
called
...
sync2files
...
which
...
contains
...
the
...
blocks
...
of
...
text
...
between
...
the
...
-begin
...
-
...
and
...
-
...
end-
...
lines
...
below
– begin –
– end –
Once the script is done, run the command
chmod u+x sync2files
Next go into ~/.ccbb-rsync-backup,
...
and
...
create
...
a
...
file
...
called
...
include,
...
and
...
a
...
file
...
called
...
exclude.
...
This
...
can
...
be
...
empty,
...
but
...
over
...
time
...
you
...
may
...
want
...
to
...
adjust
...
the
...
contents
...
of
...
these
...
files.
...
For
...
example,
...
you
...
may
...
notice
...
cache
...
files
...
in
...
your
...
home
...
directory,
...
or
...
other
...
files
...
that
...
you
...
don't
...
want
...
backed
...
up
...
(such
...
as
...
your
...
music
...
collection
...
which
...
is
...
non-work
...
related).
...
Those
...
can
...
be
...
put
...
in
...
the
...
exclude
...
file.
...
Or
...
if
...
you
...
wish
...
to
...
only
...
back
...
up
...
specific
...
items,
...
or
...
need
...
to
...
back
...
up
...
items
...
other
...
than
...
~,
...
you
...
can
...
add
...
entries
...
to
...
the
...
include
...
file.
...