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RAID 1 Failures and Data Recovery


I have a QNAP Turbo 259 server which has a pair of disks connected in a RAID 1 array. I have a problem with one of the disks, which persistently drops out of the array. This usually happens when I am working on something, researching on the internet and then trying to save the data to the Turbo, for example. These disconnection problems mean that the data on the drive is not accessible to me, since the drive will just drop out as soon as I try to open any file, and then the destination is not recognised. I keep reconnecting the hard drive to the array, and it never needs to be reformatted, it just slots back into the array on Disk Manager as though nothing had happened.


I am suffering some serious problems with a QNAP Turbo server which is not responding to my commands. I have consulted the RAID array, which shows a number of different drives, including the RAID 1 mirror which seems to be the part of the server I cannot connect with. The problem occurred when one RAID 1 disk fell out of the array, and was reported as failing. I rebuilt the drive from the remaining RAID 1 disk, and was still able to boot up due to the RAID 0 disk which held the operating system. However, I cannot access the RAID 1 disk which is where all of the data saved from my computer was stored. I have checked the logs, and found that the disk failed during a data backup process, so that information which was being transferred to the server was probably lost sometime in the night.

RAID 1 Failures and Data Recovery

RAID 1, as compared to RAID 0, is used primarily because of its high level of redundancy. RAID 1 is generally used with a pair of disks, and all data is copied in an identical manner across all the drives found in the array.

Benefits of RAID 1

The main benefit and reason that people opt to utilize RAID 1 is because of the level of redundancy provided—it’s possible to lose the functioning of one of the disks in the drive and still maintain functioning because of the data stored on the remaining drives. In the case that one of the drive fails, it’s then possible to rebuild that particular failed drive, without having the worry about the downtime that would be associated with a complete system failure.

Another benefit realized with the use of the RAID 1 array is the ability to enjoy increased read performance. This occurs because data can be read off any drive located on the array.

Often, RAID 1 is used for application servers, web servers and company servers, because of its high level of reliability. The system is popular because it is a relatively inexpensive way to have increased data redundancy and read speeds.

Disadvantages of RAID 1

Disadvantages associated with the use of RAID 1 include the potential for decreased performance. Unlike RAID 0, since RAID 1 writes data to all drives, not only is there no benefit to performance, but it can even be slightly decreased. Another disadvantage is the fact that only half of the disk storage space is available, since everything is written identically.

RAID 1 Failure

Because of the redundancy, RAID 1 is considered an extremely reliable storage system, and while this is generally true, just as with any other system, failure is possible. Since RAID 1 has a reputation as providing the utmost reliability, many times users fail to back up their systems, but this is a mistake, because even the most reliable system is susceptible to certain problems. Since RAID 1 is used for very important purposes, a failure of the system can be costly and very detrimental to a business or organization.

Just as with traditional hard drives, RAID 1 systems are susceptible to failures because of a range of logical and physical issues. Logical issues affecting RAID 1 arrays include deletions, viruses, lost partition structures and corruption. Physical issues that can impact RAID 1 arrays include, but aren’t limited to, a damaged motor, bad sectors, failures related to overheating, head crashes and electrical damage. RAID 1 can also experience failure because of power surges.

RAID 1 Data Recovery

If a RAID 1 data recovery service is required, the chances for success are fairly high and the process is simplified if at least one of the disks contained in the array is functional and has an up-to-date copy of the data. In the case that the entire array is not functioning properly, or there is a logical problem, such as a bad sector problems, affecting all disks in the array, the data recovery process is a bit more complicated, but a highly trained and expert RAID 1 data recovery service generally has a high rate of success. Manufacturers of RAID arrays differ in their designs, which means there isn’t a pizza cutter solution for the retrieval of data on a RAID 1 system. For this reason, the best course of action is to use our professional raid data recovery service, with 14 years of experience in the specific recovery of data stored on RAID 1 arrays.