Difference between RAID 2 and RAID 3
RAID is a modern technology method adopted by individuals, IT personnels, companies, data centers, and many other people. The wide acceptance of RAID storage is because of its versatility and flexibility. Also, depending on your chosen configuration, RAID can offer much bigger space than single-drive storage setups.
Generally, RAID levels utilize unique storage mechanisms, but some of them may combine two. The mechanisms are stripping, mirroring, and parity. Mirroring allows for high redundancy and easy data recovery, stripping gives you more storage space from your RAID drives, and parity gives you a little bit of time for recovery in a case of data loss.
RAID 2 and RAID 3 are types of RAID arrays, each utilizes a different mechanism for data storage, and as such, they differ from one another. The numbers “2” and “3” do not particularly have any significance to the performance of the RAID level, they are used for unique identification of the various RAID arrays used by many.
Before we head on to the main content, it is important to say that none of these RAID types replace the need for data backup, so you should always make backups of your important files to avoid losing them completely when your RAID fails.
What is RAID 3
RAID 3 is a type of Redundant Array of Independent Disks that supports dedicated parity and byte-stripping. This RAID array is rarely in use today due to its mechanism, but it’s quite a good one to set up. In RAID 3, data is stripped in bytes instead of blocks, and the data bits are spread across the storage disks, as well as the parity disk.
A dedicated disk saves the parity information in RAID 3, so even when one disk fails in the array, you can still access your files. Data is transferred in bulk and parallel in RAID 3, which guarantees some level of high speed in performance. But then, RAID 3 does not simultaneously process requests since data blocks need to be stripped, first, then spread across all disk members – in the same physical location on each disk.
Thus, RAID 3 offers significantly high-speed transfer rates, suitable for memory-tasking activities such as uncompressed video editing. However, in recent times, RAID 3 and even RAID 4 have been replaced by RAID 5, which implements the mechanisms used by the two RAID levels, while offering better performance.
Disadvantages of RAID 3:
- Uses a Separate Disk for Parity: You need a separate (dedicated) disk for parity in RAID 3, and this can lead to a potential bottleneck performance if any of the data disks get faulty.
- Slow Performance in Small Data Applications: Unless you’re setting up RAID 3 for tedious applications, using it with small-size files/data will result in slow read & write performance.
Advantages of RAID 3:
- High Data Transfer Rates: In heavy data applications, RAID 3 offers impressive read and write speeds. This RAID guarantees high data transfer rates for sequential data.
Parity: If one disk fails in the Array, you can still access your data from the other RAID 3 drives, thanks to the parity option.
What is RAID 2
RAID 2 is another type of RAID storage level that utilizes bit-level striping and dedicated Hamming code for error correction. To an extent, it is similar to RAID 3 as it also uses dedicated disks for parity (error correction). While this RAID level has gone extinct, it is worth noting RAID 2 was among the foremost adopted RAID levels.
Bit-stripping is a storage mechanism that allows data to be split into bits, and the bits stored across the disks used in the array. In other words, every disk in the array has a portion of the data stored in the RAID array; so, if one drive fails, the chances of recovering the complete version of the lost file/data are minimal.
But then, there are parity disks that store the information sent to the data disks and attempt to fix errors with your data using a technique known as Hamming code.” Also, in RAID 2, disks’ synchronization is handled by the controller, so that the data disks can spin at the same angular orientation.
RAID 2 is no longer used in these modern times because of its complex setup procedure and data storage mechanism. But it used to be the best choice for users who need more capacity and slightly faster speeds compared to what a single-drive storage will offer.
Disadvantages of RAID 2:
- High Set-Up Cost and Complex Configuration: RAID 2 requires you to buy a minimum of four disks since it will need dedicated disks for error checking and parity. You’ll be spending twice the amount you will use to set up similar RAIDs like RAID 5, RAID 1, and RAID 0.
- Currently Obsolete: Literally no one used RAID 2 currently. This is because the storage mechanism is complex and not suitable for modern applications. There are many other RAID types that offer better benefits. Even so, most data storage features offered in RAID RAID 2 are now inherent in modern hard disks.
Advantages of RAID 2:
- Noticeable High Data Transfer Rates: RAID 2 can offer high transfer rates depending on the hamming code configuration.
- Error Correction Using Hamming Code: This is basically the major offering of RAID 2. The Error Correction Code (Hamming Code) helps to detect and correct errors within the data bits stored across the storage drives in the array, which validates data integrity and accuracy when the data is been accessed.
Parity: RAID 2 uses dedicated parity disks that store the parity information for all other disks in the array. The parity information is generated through Hamming code to offer fault tolerance when one disk fails in the array.
Comparison Table RAID 2 vs RAID 3
RAID 2 and RAID 3 are pretty similar in many ways – the two RAID levels also have similar complex setup procedures. Hereunder is how they compare to each other.
Bit-stripping with ECC
Byte-stripping with dedicated parity
Minimum No. of Disks
Setup Cost and Complexity
Expensive, complex setup
Expensive, complicated setup
Performance & Speed
You may experience high performance
High speeds for sequential data transfer, but slow for random transfers
Data Recovery Differences in RAID 2 vs RAID 3
When one drive fails in RAID 2 and RAID 3, recovering the lost data is possible, but might be difficult if not done on time. RAID 2 uses hamming code for error checking and fixing, this implies that when one disk fails, you can still access your data from the RAID because the hamming code technology will attempt to restore the data from the parity disk, check for lapses, and correct them.
On the other three, in RAID 3, the dedicated parity disk allows for more flexible data recovery over the hamming code technique used in RAID 2. With a dedicated parity disk means there is more room for data recovery when one drive fails in the array. But all the same, the best data recovery approach is getting a RAID recovery program.
How to Safeguard Your Vital Data?
The best way to keep your data safe is to back them up regularly. Regular backups can be created using quite many tools out there. RAID levels do not substitute data backup, and as such, you should always make plans to save a copy of your data elsewhere. Interestingly, DiskInternals RAID Recovery can help you back up your data at any time and also help with RAID data recovery.
DiskInternals RAID Recovery
- Create multiple backups for free
- Recover files from failed RAID drives
- Built-in wizard for intuitive usage
- Preview recovered files
- Supports software and hardware RAIDs
- Runs on all Windows OS editions and Server OS versions
DiskInternals RAID Recovery is developed with a mechanism that automatically detects your RAID type, reconstructs the array, and recovers all file formats. The software can recover from both RAID 2 and RAID 3 arrays, as well as all other known RAID levels such as RAID 1, RAID 0, RAID 60, and others.
How To Backup Your RAID Data Using DiskInternals RAID Recovery?
- Download and install the software on your computer system, then launch it and connect/mount your RAID drives.
- Right-click on the drives and select “Create Disk Image”
- Choose a folder to save the image files and that’s all.
You can create disk images at random times to ensure that none of your newly saved data is lost.
RAID 2 and RAID 3 are no longer being used because RAID 5 seems to offer everything they both have to offer. The need for data backup cannot be overemphasized and DiskInternals RAID Recovery is a decent choice. Also, the software can recover files from all RAID arrays and it runs on all Windows OS systems.