Basic Guide to Computer Backups
Eric Moore Computer Users Group of Greeley September 13, 2008
Why Create a Backup?
Any hard drive will eventually fail Data recovery from a failed hard drive is expensive! Restoring a deleted or corrupt file is not always possible Your data may be time-consuming to recreate (if even possible) You depend on your computer for your livelihood You need to keep multiple revisions of a file
Backup Media
Internal Hard Drive 500 GB of storage About $0.20 per GB Fast backups and restores Not portable! External Hard Drive 500 GB of storage About $0.20 per GB Slower than internal hard drive Portable CD-R 700 MB of storage About $0.23 per GB Portable Inconvenient for multi-GB backups
Backup Media (cont.)
DVD-R 4.7 GB of storage About $0.05 per GB Portable More convenient than CD-R DVD+R Double Layer 8.5 GB of storage About $0.14 per GB Portable More convenient than DVD-R USB Flash Drive 4 to 32 GB of storage About $2.50 to $3.00 per GB Greatest Portability Pricey
Backup Methods
File and Folder Backup
Select group of files and folders Less time to perform Less storage space For small, daily backups of your data Entire partition or hard drive More time to perform More storage space For complete restoration of your computer
Drive Image
Types of Backups
Full Backup Incremental Backup Differential Backup Copy Backup
Full Backup
Captures every selected file and folder Marks every item it touches as being backed up Requires the most space and time
Incremental Backup
Captures files and folders created or modified since last full or incremental backup Marks every item it touches as being backed up Requires less space and time to complete Requires more time (and care) to restore
Differential Backup
Captures files and folders created or modified since last full backup Does not mark anything as being backed up Requires more space and time than an incremental backup Requires less time to restore
My Recommendations
Method and Media Disk image for greatest safety in case of disaster External hard drive and/or flash media Frequency Full backup at least once a month Incremental or differential once a day Redundancy Create copies to different media Store at least one encrypted copy off site or online Test for Reliability Verify scheduled backups are actually run Try restoring some files and folders