Yes, provided at least one drive in the mirrored set continues to function normally. However, if both drives fail but are still partially readable, it may still be possible to rebuild the entire data set using the readable data from both sets.
RAID 1
RAID 1 OR RAID 5 provide added performance as well as fault tolerance --- GAURAV TOMAR
It is relatively easy to replace Raid one drive with a larger Raid one drive. You must turn off your system, and take out the drive, and place the larger drive in its place. Next, you turn on the system, and install the larger drive.
RAID 6 provides the most fault tolerance of any standard RAID disk arrays (RAID 0, 1 , 5, 6, and RAID 10). If any two disks in a RAID 6 array fail and are removed, then two new blank disks can be installed and no data has been lost. RAID 1+1 or most other "layered" RAID systems can provide more fault tolerance than RAID 6, tolerating the failure of any 3 disks. Some experimental non-standard disk arrays can provide more fault tolerance with less overhead, such as the parchive system. Nearly all distributed file systems and distributed version control systems can be set up so that if one machine is completely destroyed by fire, all the data can be recovered from a backup machine in another building.
It depends on what RAID level you are planning to use. One of the most common levels is RAID 1, data is written identically to multiple hard drives. This achieves redundancy in a RAID system. It creates a duplicate, a fail safe in case of a hard drive failure.
RAID 0 is "Stripping" and RAID1 is "Mirroring". RAID0 doesn't provide fault tolerance but RAID1 does provide fault tolerance because it has a every disk has a mirrored disk so that in case of disk failure the other disk can be used.
Every RAID level stripes data across multiple drives, which improves performance compared to using a single disk. RAID 0, RAID 1, RAID 1+0, RAID 5, RAID 6, etc. all have better performance than a single disk. Other than RAID 0, all other RAID levels provide fault tolerance. RAID 1, RAID 1+0, RAID 5, RAID 6, etc. all have fault tolerance.
raid 5
To create a RAID set, first, ensure you have multiple hard drives or SSDs installed in your system. Access your computer's BIOS/UEFI settings or RAID controller interface during boot-up to configure the RAID level you desire (e.g., RAID 0, 1, 5, 10). Follow the prompts to select the drives you want to include in the RAID set and define the RAID parameters. Finally, save the configuration and exit, then format the new RAID volume in your operating system for use.
There are three types of RAID RAID 0 (Stripping without parity) The records are distributed among all the available HDDs. The number of the HDDs may vary from one system to the other RAID 1 (Mirroring) This uses double number of HDDs. One stores the records while an equal number of HDDs forms the backup. RAID 5 (Stripping with parity) This type of raid distributes the records in n-1 disks while maintaining 1 disk as the parity disk. assuming 4 HDDs are required RAID 0 uses all the four RAID 1 uses double RAID 5 uses 4 + 1
RAID 1, RAID 1 + 0, and RAID 5, 6.
Different RAID systems have different effects on multiple hard drives. RAID 0 combines storage together. Say you have 2 250GB HDDs combined with RAID 0: that you gives you, essentially, 500GB of storage. The problem with RAID 0 is that if one of the drives were to fail, then the other is to fail too, because of the way RAID 0 works by distributing strands of data over both disks. RAID 0 is sometimes not considered to be a true RAID system because of the lack of fault tolerance. RAID 1 and 5 are more complex to describe, but they generally deal with the same thing: backups. Instead of combining storage, RAID 1 and 5 deal with clones of a particular drive to offer redundancy if one were to fail. Say you have 2 250GB HDDs under RAID 1, essentially giving you 250GB of storage. If one drive were to fail, then the other would serve as a replacement if such were to occur.