RAID 5 Data Corruption: Symptoms & Precautions

Since the discovery of RAID (Redundant array of independent disk) Data storage technique, user follows the trends of having mass storage capacity as well as ability to recover his/her data from any failure conditions. The most widely used and famous RAID Storage technique is RAID 5, require minimum of 3 disks and have some key features, such as:
  • Fault Tolerance means increase data protection and integrity
  • Increase storage capacity
  • Faster performance
Many users believe that RAID drive has been made to not fault but in reality, it fails. In most of the cases RAID 5 array become failed or corrupted due to various unavoidable facts. For details, look around the topics mentioned below:
  1. When one hard drive attached to RAID servers become failed, eventually the RAID arrays will start to run in degraded mode. After which, other disks in the array will have to suffer an equal stress which results in failure of second hard drive. So, consecutive failure in two drives attached to RAID arrays will leads to RAID 5 array failure.
  2. RAID 5 controller failure
  3. Any power surges, occurs with RAID 5 controller can malfunction RAID elements, RAID configuration or the hard drive itself.
  4. Sometime, in an attempt to rebuild failed RAID arrays, you may enter wrong RAID parameters, which causes a sudden breakdown and complete system failure.
  5. Logical corruption such as virus/malware attack, hard drive crash, human errors, RAID partition table corruption etc. Though, RAID Drives are made with fault tolerance which protects only physical failure but could fail in case of logical failure.
You should avoid doing any of the following activities to stay away from any data loss situations:
  1. Stop using RAID drives in case of a single hard drive failure. Any remedial actions on such conditions will leads to damage on second hard drive and failed RAID arrays.
  2. Don't try to remove or alter any hard drive attached to RAID arrays while system is performing any read/write operation.
  3. Always remember or note down the various RAID parameters which greatly helps to successfully rebuild corrupted or failed RAID 5 arrays. The possible required RAID parameters could be :
  • Disk Order
  • Stripe Size
  • RAID Header Size
  • Parity Rotation
  • Parity Delay
   4.  Do not operate any chkdsk or similar disk checking operation, as this command will run 
        in write mode and heavily responsible for overwriting the failed hard drive data.
   5.  If you've loose any important data from failed RAID arrays, it's advisable to wisely 
        choose any data recovery software.
 

P.S.: To recover data from failed RAID arrays using RAID recovery software, you are 
        also required to enter the correct RAID parameters which I have already described in #3. 

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