RAID is the acronym for Redundant Array of Independent Disks. A RAID 1, RAID 5 or RAID 6 disk array, using two or more disk drives storing enough redundant information to permit continued operation through at least a single drive failure and subsequent rebuilding of a replacement drive, is a great image file and video storage option and I highly recommend implementing it. But, a RAID array featuring mirrored drives (RAID 1) or a parity drive (RAID 5) is not, alone, enough protection. Here are some reasons why:
- RAID does not protect from inadvertent file deletion or other issues including undetected/accidental drag and drop. In a RAID system, all copies of data are immediately treated the same, with the redundant file and/or parity information being updated at the same time as the primary drive information. You will likely find yourself needing to retrieve a copy of a file from a backup more frequently than you will have the drive failures that RAID strategies protect against.
- RAID does not protect from malicious viruses.
- RAID does not protect from fire or other disasters.
- RAID does not protect from theft or other intentional destruction.
- RAID does not protect from data corruption. I have a long IT background and have multiple times lost servers due to RAID array corruption. While this should not happen, one of Bryan's Laws of Photography comes into play here: "If it can, it will."
- RAID does not always protect from a second drive failure prior to recovery from an initial drive failure. While the odds of two drives failing within a short period of time may be low, drives in a RAID array are often aging at the same rate and influenced by the same factors including power and heat issues. A friend just lost 3 of 5 drives in a name brand RAID array due to a firmware/software issue.
Your RAID array must
be backed up frequently and at least one current backup must be stored securely off-site. Look at what you have at stake (your entire image collection?) and implement a backup strategy that adequately protects those assets.
What are the backup options for a RAID array?
RAID array backup options include:
- External hard drives including external RAID arrays
- Network attached storage including network attached storage drives
- LTO tape drives
There are online/internet backup options available for those fortunate enough to have adequate internet connection bandwidth, but if relying solely on an online service for your backup needs, you must have a great deal of trust in the company you are purchasing this service from. These companies can vanish at the throw of a switch. Also, make sure that some form of file archive access is provided to protect against inadvertent file deletions, etc. from being replicated to the service.