Shulou(Shulou.com)06/02 Report--

Physical failure of 1.RAID controller

If there is a physical fault in the RAID controller, it can not be recognized by the computer, and it will not be able to control each physical member disk in the RAID-1. In this case, the virtual logic disk through the RAID controller naturally does not exist.

2.RAID message error

For hard RAID-1, after the RAID controller configures the physical disk as RAID-1, it records relevant information about the RAID-1, including the number of physical disks that make up the RAID-1, the capacity of the physical disk, which physical disk is the working disk, which physical disk is the mirror disk, the starting address of the RAID-1 in each physical disk, etc., all this information is called RAID information, also known as raid metadata. They are saved to the RAID controller and sometimes to the member disk of RAID-1.

Knowledge of disk array raid1 and explanation of data recovery

For soft raid-1, there is also the RAID information mentioned above, which is generally stored in the member disk of RAID-1.

The error of RAID information means that there is an error in the configuration information of the RAID-1, which leads to the failure of the RAID program to organize and manage the member disk in the RAID-1 correctly, resulting in the loss or inaccessibility of the RAID-1 logical disk.

Physical failure occurred on 3.RAID-1 member disk

RAID-1 allows one of the member disks to go offline. If a member disk in the RAID-1 has a physical failure, such as circuit damage, head damage, firmware damage, bad sector, etc., the member disk cannot be used normally, but the data in the remaining member disk is intact and the RAID-1 will not crash.

If the system administrator does not replace the failed member disk in time, when another member disk fails and goes offline, RAID-1 will crash completely.

4. Human misoperation

If you unplug both member disks in RAID-1 by mistake, or accidentally delete the configuration information of RAID-1, RAID-1 will crash.

The idea of RAID-1 data recovery

RAID-1 is the simplest of all RAID. Take the RAID-1 structure in the figure as an example. It can be seen from the figure that the two hard drives in RAID-1 are mirrored each other, and all the data are exactly the same. If the RAID controller failure or RAID information error causes the RAID-1 data to be inaccessible, just remove one of the two physical disks from the server and connect them to a computer as a separate hard disk. It's easy to recover the data.

After the collection of the above information. Summed up the simple recovery ideas, recovery must have the following conditions.

1. The replacement hard disk should be the same type, the same series and the same capacity.

two。 The hard disk is a brand new hard disk or an unpartitioned and unformatted hard disk

3. The hard drive needs to be plugged back into the original RAID channel.

4. Some soft arrays need to enter the WINDOWS system to synchronize RAID1 automatically.

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