AMITIAE - Thursday 21 October 2013
System Preferences in OS X 10.9, Mavericks: Time Machine
By Graham K. Rogers
With Mountain Lion another useful option appeared - the ability to use more than one disk for backing up.
Setting Up (1)When Time Machine is first opened on a new installation there are two parts to the panel displayed: Off/On to the left below a large Time Machine icon; and the main information display area. Initially, the larger part of the panel will have a Time Machine disk icon above a button marked Select Backup Disk.
In this original setup condition, the main panel has a revised text description of the feature. At the bottom is a check box for display of the icon in the menu bar: this menu bar icon provides other controls when active. These are related to the Preferences, but are not identical.
Changing Off to On (or using the Select button) reveals a panel in which a user may highlight a suitable disk for backups to use. Initially this also has an icon for Time Capsule - Apple's hard disk and Wi-Fi combination. Any suitable hard disk attached will also become visible.
Suitable hard disks may include a flash drive if it is formatted as Mac OS (Extended) although for all practical purposes this may be too small. For suitable capacity, disks of at least 500 GB or more are essential.
The panel revealed when selecting a disk for the feature will depend on the type of computer: a notebook, for example, will have a checkbox to allow use of the backup disk when using battery only.
While Time Capsule is ready to run, a hard disk purchased from a store may need to be partitioned. This may be done beforehand in Disk Utility (in Applications > Utilities) and choosing the Partition tab. Once the size of the partition (or partitions) is decided, the Options button should be pressed. A user should choose Apple Partition Map or GUID. However, when experimenting in Mountain Lion with a new disk that had a partition in the FAT 32 format, Time Machine set this up for me without the need for my intervention.
The system recognizes any disk made available and the main part of the panel changes. The disk icon is moved to the left and details of the disk used are displayed: Name, Available (disk space), Oldest Backup and Latest Backup. "Next backup" is available when only one disk is used. During backups, a progress bar is displayed.
Setting Up (2)The main panel also has two buttons which open further panels: Select Disk and Options (see below). The Select Disk panel can be used to add a second disk and is almost identical to the original "Select Disk" panel when Time Machine is first set up.
The ability to use more than one disk offers a number of possibilities, such as backup disks in separate locations; or an easy transition from a full disk to its replacement.
The disk can be used to backup more than one Mac, although space will obviously become a consideration sooner or later. Backup files are stored on the external disk in a Backups folder. Inside that are separate folders for each Mac.
When a second disk has already been added, a disk icon below the nominated disks shows, "Add or remove backup disk." Pressing this reveals the same panel as above to allow another disk to be added (or one to be removed).
Backing UpThe Oldest Backup will change as the disk is filled and weekly backups will be deleted. The Time Machine panel shows the last time the disk was backed up. "Next" displays the time when the next backup is scheduled to take place. If a disk is not connected, the panel shows that the next backup will occur when a disk is available.
The first backup takes a long time. If there is more than one partition on the external disk, the transfer may be slowed if Spotlight indexes the others. Spotlight preferences can be used to drag the partition icon to the "Privacy" panel. Indexing will stop.
In earlier versions of OS X, whenever the disk was connected, the entire system was backed up every hour, every day and every week. Time Machine does not create a total clone. Any changes are recorded and Time Machine uses those for an incremental backup. The preferences panel does not have to be open for backups to occur.
To force a backup, we can use the Backup Now item in the Dock or the menu bar icon menu. If a backup fails, information appears in red, with the letter i in a red circle alongside. The "i" can be clicked on to reveal more information about the problem. Trying again (or perhaps a restart if this is persistent) should clear the problem.
Two checkboxes at the bottom of the "Exclude" panel are marked "Back up while on battery power" (not on desktop computers); and "Notify after old backups are deleted." As the disk becomes filled, so the earliest backup will be removed to make room for the current ones. This is a warning that it is time to obtain a new disk.
Full disk warning from an earlier installation
RestoringTo return to a previous version of a file or folder, we access Time Machine via the Dock (or the menubar) icon. This brings up the "Infinity" window and we may select a file from the Finder panel and a time: either by using the control to the right, or by clicking on the receding panels.
When a file is located we may click on Restore and the file will be moved to its earlier location. If a file of the same name already exists in that location, we are given the option to rename the file to be restored, or to save it elsewhere.
This feature works best when a disk is attached, but it will function up to a point without. In testing I have been able to return to previous file backups with no Time Machine disk attached. Even this can be a lifesaver, for example with a version of a file, or an item that was accidentally put in the Trash. When this feature of Time Machine is used without a disk attached, some of the Finder panels in the "Infinity" window are black instead of grey. These parts of the backup are unavailable until the disk is attached.
This may also be done on a computer that already has the system. Time Machine will replace all data, including settings and accounts. There are several warnings before this takes place. A warning appears to inform us that taking this step will replace all the contents of the selected volume.
Note: this does mean that everything previously on the disk will be lost during the replacement process. Pressing Continue brings up a panel that shows any suitable disks available. To effect the backup, if not already in use, the disk that contains the Time Machine backup can be attached at this time.
When the disk is recognized and highlighted, pressing Continue gives a list of available backups. A full restore is likely to take a considerable time. Attaching a power supply is strongly suggested. When the process is complete the computer will restart with the restored system.
When using a Time Machine backup to setup a new computer, the Migration Assistant Utility must be used.
NotesDespite the availability of Time Machine and a number of other backup solutions, I am often reminded that people do not regard this as a necessary part of everyday computing. I have had a burglary, two disk failures (different computers and 3 years apart) and in all but the first, I was able to recover. In the first disk failure, Time Machine helped me switch from a 15" to a 13" MacBook Pro and then when the repair was effected, back to the 15" - I hardly missed a beat and lost no data.
I asked a class of engineering students about this recently and was greeted by laughter. It is usually something that happens to other people.
There are frequent tales of stolen or lost computers (same thing really), broken machines, files over-written, accidental deletions and other causes of lost data.
A backup plan is essential.
Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand where he is also Assistant Dean. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs.
For further information, e-mail to