Is my data safe in a RAID enclsoure?
The answer to this question depends on the RAID mode you are using and the cause of the data loss. In general, when using a RAID mode with redundancy in our 2-bay and 4-bay RAID enclosures (e.g. RAID 1 or RAID 5), your data is secure as long as only one drive at the time fails.
In other words, the RAID enclosure is a backup for hardware failure of a single drive. It does not protect against loss of more than one drive at the same time, a defective RAID controller, data deletion by accident or lost data due to a virus or data corruption.
Not all of the available RAID modes provide data redundancy. If you select a mode designed for performance or storage capacity (e.g. RAID 0 or JBOD), even the failure of just one drive means your data is lost. With Non-RAID, if available in your RAID enclosure, you only lose the data on the drive that has failed, the other drives are not affected.
Defective RAID Controller
Even though this does not happen often, it's still a possibility that one day, your RAID controller may fail. In most cases, the only way to access your data again is by installing the drives in another RAID enclosure with the same chipset, same firmware and same RAID setting.
There are exceptions to that rule. As an example, if you are using RAID 1, it creates a mirror copy of your data on the second drive, which you can also access independantly. Another example is Non-RAID. If the hardware fails, you can simply take out one of the drives and install it in a simple USB enclosure or even inside your computer to access the data.
Also, with help of a data recovery service, you might still be able to recover the data but this is not something we can recommend and there is no guarantee that it will work. Additionally, services like that are usually expensive.
Preventing Data Loss
It’s always best to keep a second copy of your data in a different location. This can mean that you keep the original data on your computer or make a second backup somewhere else. Doing so makes it possible to easily and quickly recover your data even if you accidentally delete files, the data on that drive gets corrupted or something else happens to your hardware and hard drives (e.g. natural disaster).
Preparing enough storage for a second copy may be expensive up front, because you need to either buy a larger drive for your computer or a second external storage solution but if your data is valuable, it is well worth the investment.
If you currently don't have another backup location and there is not enough space to keep the original data on your computer, consider buying a second RAID enclosure and another set of drives at the same time. Buying the same RAID enclosure for the second backup has the additional benefit that it can act as a backup for the hardware too (e.g. same RAID controller, same power supply).