Scott Hanselman wrote up a post on his backup strategy for all the computers in his home, which relies mostly on Mozy.com and Windows Home Server.
I have lost data numerous times in my life, but my first serious effort to backup up my data occurred after 1995. In that year, after installing a new operating system, I lost all my pre-1995 data—all information about my life up to 1995 disappeared forever.
Loss of data happens to companies too. WordStar lost the source code to its wordprocessor, which, at one time, was the market leader. Excel’s source control system once failed spectacularly and the whole system had to be reconstructed from an out-of-date enlistment from one individual’s machine.
There are several goals in my backup strategy.
- Backup to multiple media… USB, external HD, DVD, Mozy.
- Different media have different risks. Removable media like DVDs and USB are high risk. They are easily lost. Sometimes files can no longer be read files from an USB flash drive or a DVD from the same drive it was burned in. This could be due to chemical breakdown, exposure to inhospitable environments, or other damage.
- They may also have limited lifespans with some technologies only lasting a few years. DVDs come in different grades—gold DVDs last the longest, with some companies claims of 300 years, but no one has been around to verify that claim.
- I discovered my development files I read from a backup DVD were corrupted, even though they were successfully verified after being burned; I was also able to reproduce the file by burning to a .ISO disk image file. The problem appeared to be in reading the files from the disk. Even though file header information remained the same, contents of other files appeared in place. The DVD burning software was from a reputable company that specializes in CD burning.
- Unless you have restored data previously, you can never be sure that you be sure that you backed up what you have intended.
- Offsite backup… I use Mozy to backup my files to an offsite location, in case a catastrophe impacts my home. However, I don’t rely on an outside party to keep my data for a number of reasons, most of which I have encountered:
- I have read of instances in which a blogger stored data through a service provided by Google and lost it all.
- Forgotten usernames and passwords. This could easily occur if password information is normally cached by the backup software, and a catastrophe destroys all records of that information. I tend to use the same username and password for all backup sites
- Expired service or reinstalled service.
- Backup schedule not followed. Software fails to performed for various reasons such as bugs, incompatibilities with the latest operating system, network service, firewall and security issues.
- Omitted files. Backup software tend to have confusing interfaces and terminology such as backup sets, etc. They often also include file filters.
- * Backups at different points in time… Maintain separate backups of data at different points in time.
- Automated daily backups… It wasn’t until the past couple years that I used automated backups to store. The advantage of automated backups is that they can be done daily without manual intervention or appreciable impact on my day-to-day work. The one issue is to periodically review that backups are taking place and note any errors encountered.
- Continuous backup… I use a mirrored RAID-1 drive to provide real-time redundant storage for all my important documents, development files, and emails. Terabyte drives cost under a $100 nowadays.
For my current setup, I have a
- Mozy online account, unlimited for $50 dollars/year
- 2 x 1.5TB drives in a raid array with a 1 TB of striped RAID 0 storage for my system partition and 1 TB of mirror (RAID 1) storage for data partition.
- I currently backup my files using Retrospect Express and Windows Backup to my 500GB and 200GB USB external portable drives. Windows Backup saves system images but I also backup my document files with it for redundancy.
- Monthly, I copy files to my USB flash drives and burn files to a combination of CDs and DVD+Rs (single and dual layer) diskettes depending on the size of the folder being copied.