You will know the importance of having a backup of your data if you have the experience of losing your data due to a hard disk failure or disaster. Your backup strategy is necessarily different from others due to each individual’s appetite for risk, the budget and the amount of data. You need to formulate a method that suits your own need and we hope the following guide can be helpful.
We use the following as scenario for our typical Mac user who owns a MacBook Pro with 320GB internal drive. This user also has 1TB of external hard disk for his/her music, photos and movies. This external drive is attached to the MacBook Pro via Firewire and currently contains about 600GB of data.
Use Time Machine for Incremental Backup
Time Machine is a great backup software which does incremental backup on an hourly, daily and weekly basis. It allows you to restore back for example files that you deleted 2 hours ago with a ‘time machine’ user interface. It is best suited for backup of data that changes regularly, such as your documents and presentation files.
To use Time Machine, you need to purchase a backup disk. This disk can be an external USB/Firewire hard disk, or a NAS. To ensure that Time Machine does its backup, this backup disk is required to be connected to the Mac. We recommend an always on NAS for this purpose. Please note that not all NAS support Time Machine, check the spec before purchase.
Typically it is recommended for the Time Machine backup disk to have 1.5 times or more the capacity of the data amount. For example, if you have 1TB of data, it is best to get a minimum 1.5TB of capacity for your Time Machine backup disk. The bigger the backup drive, the older the data Time Machine can store on the disk.
You might want to use Time Machine only for data that changes frequently. Time Machine allows you to selectively include and exclude by folders which data to backup. If your movie library rarely changes every month, then it probably is covered by the following clone method of backup.
Create Clones of Hard Disk Monthly
Purchase an external USB hard disk with a capacity greater than 320GB and use software such as SuperDuper! or Carbon Copy Cloner to create a bootable clone of the internal 320GB hard disk. The clone disk will have the same data as the internal drive, and allows you to boot from it via USB. The internal drive is cloned once every month.
Purchase an external USB hard disk with a capacity of 1TB and use software such as SuperDuper! or Carbon Copy Cloner to create a clone of the external 1TB hard disk. The clone disk will have the same data as the external 1TB drive. The 1TB drive is cloned once every month.
For extreme measure and offsite backup purpose, you might want to create an additional clone. Label the clone disks “Odd Month” and “Even Month”, and alternate the disk each month for the clone backup.
Updated: There is an email enquiry questioning the ability of Mac booting an OS from external USB drive. Yes, all modern Intel CPU-based Mac is able to boot up OS from an external USB drive.
Offsite Backup of Data
We recommend offsite backup of your data, for the occasion when your home is destroyed by disaster or accident. Typically you keep one copy at home and one copy offsite such as in the office. Keep the clone disk “Odd Month” at home, and keep the clone disk “Even Month” in the office.
Archive Your Data
Data grows, and to keep data manageable, you might want to archive your data. Archiving data can simply means moving unused data out to external USB hard disks. Archiving can be done half yearly or yearly depending on the amount of data. For easy retrieval, create yearly folders on the external disk such as “2010”, “2011” and put the archive of the year under respective folders. And yes you need to have a second USB hard disk for a duplicate of the archived data.
The above backup plan might be extreme to some but it is comprehensive enough for you not to have any worry about loss of precious data. The plan might not suit your need but it illustrates methods and backup area for your consideration. Whatever, if you do not have any backup, please start one today before its too late.