Advantage of Larger Cache
Areca offers hardware RAID controllers which may include larger cache options that can generally improve performance, as it allows the controller to store more data before it has to be written to the hard drives. This can help to speed up write operations and reduce the likelihood of data loss in case of a power failure when paired with a battery backup module.
In a RAID 0 setup, data is striped across multiple disks, with no redundancy, meaning that if any disk fails, all data in the array is lost. Writing data to a RAID 0 array requires storing the data across the disks, which can be a time-consuming process. A larger cache can help to speed up this process by temporarily storing the data before it is written to the disks, reducing the time it takes to complete the write operation. It's important to note that RAID 0 does not provide any data protection, and any disk failure will result in data loss. In such a setup, a larger cache can help to improve performance but does not add any redundancy.
In a RAID 5/6 setup, data is striped across multiple disks, and one/two disks are used for redundancy, so that the array can withstand the failure of up to one/two disks without losing data. Writing data to a RAID 5/6 array requires computing parity information and storing it across the disks, which can be a time-consuming process. A larger cache can help to speed up this process by temporarily storing the data and parity information before it is written to the disks, reducing the time it takes to complete the write and parity operation.
In a RAID 10 setup, data is mirrored across two separate sets of disks, with the data striped across each set. This provides both data redundancy and performance benefits, as data can be read and written to both sets of disks simultaneously.
A larger cache can help to speed up write operations in a RAID 10 setup by temporarily storing the data before it is written to the disks, reducing the time it takes to complete the write operation. However, it's important to note that the specific performance improvement will depend on the specific workload, the size of the cache, the number of disks in the RAID 10 setup, and other factors. Additionally, a larger cache will consume more power and may be more expensive, so it's important to carefully evaluate the cost/benefit trade-off.
It's also important to note that RAID 10 provides good fault tolerance, as the data is mirrored across two separate sets of disks. In the event of a disk failure, the system can continue to operate using the data stored on the remaining disks, with no data loss. A larger cache can improve write performance, but does not impact the data redundancy provided by the RAID 10 setup.
In summary, Larger cache can improve write performance and increase responsiveness of the RAID array. However, it is important to note that the specific benefits will depend on the specific workload, the size of the cache, the number of drives.