RAID Array Metadata: What Is It?
Here you will find out:
- what is RAID metadata
- what is Linux mdadm RAID metadata
- when DiskInternals can help you
Are you ready? Let's read!
What is RAID metadata?
Talking about RAID metadata is a bit wrong, as they apply to every disk in the array. In this way, metadata accesses the disk to convert the physical block. In other words, these are the structures on the disk for marking up the array, to indicate its type, size, an order of disks, and where each disk is.
Each file is an integral part of the file system, and it is processed by the operating system. At the same time, RAID does not know anything about files; only the operating system can put data in blocks on the disk.
A RAID controller (which contains the number of disks, the size of the strip and the order of disks, etc.) plays the role of an interface between the array and the OS, and the OS writes information blocks on it.
Many people incorrectly think that if, for example, RAID 5 crashes a disk with metadata, then recovery will not occur. Metadata is usually equal to the combined sum of three other disks and in the event of a single disk failure, you can change the sum to have a sufficient level of fault tolerance.
It should be noted that as the RAID level increases, read parallelism increases, and write performance in most cases decreases.
Linux mdadm RAID metadata
All information about the array in the Linux software RAID array is in the superblock. Depending on the version of metadata, this information will be in different positions. The superblock can first start from 128 KB to the end of the device or no later than 64 KB to the end of the device.
There are currently two supported external metadata formats, in addition to native formats for RAID volume metadata:
- DDF (disk data format) is the industry standard
- Volume metadata format based on Intel Matrix RAID
RAID array data safety
DiskInternals RAID Recovery is a professional and advanced application that can perform recovery of all data at any RAID level. You can also create a disk image at no cost; this feature is the most popular among customers. The program is developed using the latest technology and is as automated as possible. A reliable Recovery Wizard will help you make each step of recovery simple and successful.
Therefore, if you have little knowledge about how to restore an array, you can safely rely on the Recovery Wizard. A free preview of files before export is also available to ensure the integrity of the recovered files. All important parameters and configuration items of the array, such as array type, RAID controller type, disk order, size bands, etc., are automatically detected.
Below is a guide for working with DiskInternals RAID Recovery:
Download and install DiskInternals RAID Recovery. After that, launch the application and run the Recovery Wizard.
Connect the RAID’s drives to an individual disk.
A new RAID disk will be added to the disk list.
Use Reader or Uneraser mode to open the logical disk. The logical disk is contained in the Hard Drives section of the disk list from the RAID drive.
After scanning, browse the search results for free and make sure that everything is in order.
After that, purchase a license on the site to complete the export of data to the desired storage location.