In Part 1 we covered getting your Mac running with Time Machine to allow us some time to give you a fuller explanation of backups and storage, and put you in a position where you’d have sufficient information to set up a system that gives you the right level of protection for your needs.

Today, we wanted to give you some basic information in the main areas we’ll be covering in coming posts.


Equipment failure or data loss can (and does) happen to anyone, at any time (and often at the worst possible time). It’s impossible to predict every computer problem, disaster scenario or stupid human error and its therefore impossible to ensure you don’t suffer a problem. But you can make it easy to recover from these situations with a good storage and backup setup.

To keep your data safe, you should follow a three-part plan that includes versioned backups, a bootable duplicate, and offsite data storage. In addition we would recommend protecting your data by utilising RAID storage to reduce the risk of data loss.

Introduction to RAID Storage

In our next post in this subject we’ll explore storage in more depth, but right off the bat we want to suggest strongly that you protect as much as your data as possible using RAID systems. RAID stands for (depending on who you ask) Redundant Array of Independent or Inexpensive Disks. Where it gets confusing is that there are many ‘levels’ of RAID protection, some offering absolutely no protection against disk failure at all! The levels of RAID alone could fill a blog post up on its own, but we’ll summarise for you as follows:

  • RAID 0 offers no protection against data loss, but improves disk performance
  • RAID 1 offers full protection by mirroring two drives (two copies of everything). Two 1Tb drives in RAID 1 format will give you 1Tb of usable storage.
  • RAID 5 is where you really begin to get the benefits of multiple drives. Your data is spread across the drives for both performance and integrity improvements. If one drive fails, you will still have access to all your data, and replacing the failed drive will rebuild the protection again (often with no interruption to your work).

That’s a really basic summary, but we will be coming back to this next time.

Versioned Backups

Versioned backups let you recover copies of files as they existed at some point in the past. They protect you against inadvertent file changes ore deletions, even those you don’t notice right away.
Time Machine is the most common, and easily accessible system for this form of backup but there are many other Mac backup apps that support versioned backups, including:

  • ChronoSync
  • CrashPlan
  • Data Backup
  • DollyDrive

We suggest updating your versioned backups at least once a day, preferably much more often. Some backup apps automatically save new versions every few minutes (e.g. Time Machine backs up once every hour while the drive is connected), or every time a file changes.

Bootable Duplicate

A bootable duplicate (sometimes called a “clone”) is an exact copy of your startup volume, stored on an external disk in such a way that you can boot your Mac from it if necessary. Duplicates enable you to get back to work quickly if your primary disk dies—without waiting hours or days for all your files to be restored.
Two popular Mac apps that specialize in bootable duplicates are SuperDuper and Carbon Copy Cloner—but others can do this as well. You cannot create a bootable duplicate by dragging and dropping files in the Finder, and neither Time Machine nor CrashPlan can create a bootable duplicate. Time Machine however is sufficient for the majority of Mac users to recover from if the time required to recover is not critical to them financially (as it would to, say, a designer or photographer)
Each duplicate must be stored on its own volume (disk or partition). You should update your duplicate regularly — and certainly before any significant OS X upgrade.

Offsite Storage

If a fire, theft, or other disaster wipes out your computer and your local backups, you’ll be glad to have an extra backup that was stored somewhere safely offsite.
One easy way to get offsite backups is to use a cloud backup service such as CrashPlan Central or Dolly Drive—in addition to local backups. The initial backup may take weeks, but thereafter, ongoing backups should be quite speedy.
Alternatively, you can physically rotate hard drives to another location once a week or so. Link up with a local business or friend and exchange backup drives regularly to make sure you are both protected.

Backup Hardware

An external hard drive is usually the best place to store backups. Using Disk Utility, you can divide a disk into two partitions—and then store your versioned backups on one and your bootable duplicate on the other. Be sure to select a drive with space for all your current data, plus room to grow.
Those with huge quantities of data may need storage devices that combine multiple hard drives in a single assembly.


That’s it for this week, there’s plenty more to come in this series and as always, if you have any questions please contact us!