How can I get more info on my Time Machine backups?

We assume that Time Machine is already configured, either via the corresponding control panel in System Preferences or via the Time Machine Editor utility available in our Managed Software repository.

The Time Machine control panel just gives access to the most important info and configuration of your Time Machine backups like the target volume(s), automatic or manual schedule, and excluded folder herarchies. Using the command-line utility tmutil, we can learn (and customize) more. Some examples:

Show the backup targets

tmutil destinationinfo

returns a list of backup destinations. My office Mac for example tells me

====================================================
Name          : share
Kind          : Network
URL           : afp://bs@nassrv._afpovertcp._tcp.cpfs.mpg.de./share
ID            : 3944C182-5A5E-4BE1-8148-D3255B1B9F2B

Great, so Time Machine backs up to nassrv.cpfs.mpg.de to a volume called share using the Apple Filing Protocol (afp). The backup is owned by me, username bs.

Time Machine can backup to multiple destinations. In that case, a response could look like this

====================================================
Name          : share
Kind          : Network
URL           : afp://bs@nassrv._afpovertcp._tcp.cpfs.mpg.de./share
ID            : 6010B700-453A-4687-AED0-260D52849154
> ==================================================
Name          : Bay 3
Kind          : Local
Mount Point   : /Volumes/Bay 3
ID            : 927A437B-1658-4C12-ACDB-ECF6EC8E31A6

so a network backup plus a backup to a local volume is made. (The example is from a network server where multiple backups to different locations are crucial.)

Show available backups

tmutil listbackups

returns a list of completed backups on a local backup volume. For network backups, first mount the destination volume, typically on /Volumes/share (start a backup with tmutil startbackup to get it mounted), then use

tmutil listbackups -d /Volumes/share

Show local snapshots

When for example none of the destinations volumes are available, Time Machine creates “local snapshots” to be synched with a destination next time one is available. To get a list of these, do

tmutil listlocalsnapshots /

More

There is more to tmutil, in particular means to manipulate existing backups. Care has to be taken to avoid data loss, so if you are in need of these advanced options, get in touch with me.