RAID is a technology in computer data storage that is used to implement the fault-tolerant feature of computer storage media (mainly hard disk) by using data redundancy, either by software or by a separate RAID hardware unit. Simply to put, RAID is a way of combining a bunch of hard disks to form a “virtual” drive. The goal is not just to gain more space, but also to build data protection with redundancy / duplicate data functions in additional drives.
Therefore, if one of the drives fails / downs, the data will remain secure and available. However, the potential for data loss is still possible. One of the causes of RAID data loss is RAID server failure. When RAID server fails, it is necessary to document the order of the drive before deleting it from the server as well as the raids configuration and other information will be very helpful to do the RAID server recovery.
Here are some certain conditions of RAID server recovery we can learn and understand:
- If there is one disk failure, RAID server runs in degrade mode, and requires little important data. In this case, data recovery can be done completely without sharing RAID server. Copy the data immediately without rebuilding the data. But if any other disks fail, the complete RAID server will fail.
- If there is one disk failure, RAID server is in degradation mode, but you need everything including applications to boot-up operating system. This is a condition where RAID server is a either data or app server. Thus, recovering data is not enough. Try to rebuild the damaged RAID volume and be sure to back up the disk image before rebuilding.
- If the disk volume on the RAID server is lost, this type of damage can be caused by loss of RAID configuration settings, some disk failures, power surges, system crashes, or other unknown reasons. If this condition happened, should we find a professional to do the RAID server recovery procedure for preventing the loss of all data in your RAID server.
To avoid RAID server failure, first, make sure that all drives have been spun down and there is no power coming into any of them. Some RAID servers are configured to perform automatic reconditioning if it’s comes back online.
If a stale drive is in array, this will be the end of any possible data recovery. The RAID server also be configured to do a background surface scan of each drive that can damage any suspect media in the future. Before performing any type of initialization, reconfigure, scrub, or other different RAID reset functions, back up the drive.
Remove the drive from the enclosure. Then place the drive on a different computer and use the sector based on sector software, create an image of each drive. Then, check the backup and data carefully. Do not just look at the tree, look also at the folder and make sure the data is there. This way you will know if the data has been updated and you can start the migration process if you can not get RAID server to go back online.
RAID servers are in great demand around the world. Although intuitive, there is a possibility where you end up with a RAID server failure. With those following steps mentioned to perform RAID server recovery, hopefully can prevent from total data loss.