In a RAID 5 configuration, data is distributed across multiple hard disks in such a way that if one disk fails, the data can still be recovered from the remaining disks.
When a hard disk fails in a RAID 5 configuration, the system will typically generate an error message and display it on the screen or send it to a system log. The failed disk will also be marked as "failed" or "offline" in the RAID configuration.
The RAID 5 configuration will continue to function with the failed disk, but it will be operating in a degraded state, with reduced performance and increased risk of data loss.
To restore the RAID 5 configuration to a healthy state, the failed disk must be replaced and the data must be reconstructed onto the new disk. This process is known as rebuilding the RAID array.
The RAID controller will typically start the rebuilding process automatically when a new disk is inserted into the system. The rebuilding process can take a significant amount of time, depending on the size of the array and the amount of data that needs to be reconstructed.
During the rebuilding process, it is important to ensure that the remaining disks are functioning properly and are not at risk of failing. If another disk fails during the rebuilding process, the data may not be recoverable, and the entire RAID array may be lost.
It is generally recommended to have a backup of important data in case of a hard disk failure in a RAID 5 configuration, as there is always a risk of data loss when using RAID.