A redundant array of independent disks (RAID) is a reliable way to improve the performance and reliability of servers. A RAID stores data by using a collection of multiple drives. It can be used to store the same data on multiple HDDs or SSDs via mirroring, so it provides redundancy against data loss. Depending on the type of RAID you have, the performance, fault tolerance, and reliability of your servers will improve. Advanced RAID configurations like RAID 5 can provide both improved performance and redundancy. You can configure different RAID levels in your storage arrays, each providing different functions. Though there are different RAID configs, configuring RAID in windows and configuring RAID in linux devices is not much different.
RAID configurations have different levels. The common RAID levels are:
In a RAID 0 configuration, data is split into blocks and striped evenly across multiple disks in an array. The striping causes the array to act as a single disk where all the data is stored. With data striping, there will be improved read and write performance, especially for larger files. RAID 0 is one of the most cost-efficient RAID levels, but the configuration has neither redundancy nor fault tolerance. So, in a RAID 0 configuration, if a single drive fails, then all the data stored in the RAID will be lost.
In RAID 1, data is mirrored across two or more disks. This results in poor write performance. However, the read performance will be nearly two times that of a single disk. If there are more than two disks used in a RAID 1 configuration, the write performance will degrade even more, and the read performance will increase according to the number of disks used. RAID 1 is reliable due to its redundancy. If a single drive fails, the data will not be lost as a mirrored disk has the duplicate data.
RAID 5 is the most common RAID level. As it uses both striping and parity, it is a fast, reliable, secure configuration. To configure this level, 3-16 disks are required. The data striping facilitates higher read performance rates as different disks in the array can perform the read functions simultaneously. The parity function enables redundancy as the parity bits will be distributed evenly across the disks. So, if one disk fails, data can be recovered from these parity bits.
In RAID 5, if a drive dies and needs to be replaced, this is a tedious process that will take at least a few hours. If a second drive fails before the first is replaced, all data in the RAID 5 configuration will be lost. However, a RAID 6 configuration uses two parity strips instead of one, so it can withstand two disk failures at the same time, reducing the risk of data loss.
RAID 10 is referred to as a nested or hybrid level because it combines two RAID levels. In a RAID 10 configuration, RAID 1's mirroring and RAID 0's striping are combined to provide both redundancy and improved performance. This is a complex array as it needs four drives and a disk controller. RAID 10's mirroring and striping configuration results in improved performance and increased read and write speeds because data can be accessed from multiple disks at the same time.
RAID 01 is the same as RAID 1, except only half the disk capacity is utilized to mirror the data. RAID 01 mainly mirrors the striped data. Multiple disks are striped together into sets and are mirrored together. RAID 01 needs at least four disks. This configuration has good fault tolerance capabilities, so the loss of one drive will not affect the RAID's operations. But if one drive from each set fails, the RAID will cease to function.
Latency is the time it takes for data to be read from or written to a disk. It is usually measured in milliseconds. Analyzing the latency data helps you pinpoint the cause of latency, thus enabling you to troubleshoot the issue sooner.
Monitoring the disk space utilization of a RAID helps in determining the disk space used up and in forecasting when the disk space might run out. It does not bode well for a business if its RAID runs out of space without warning. Thus, monitoring disk utilization is absolutely critical in RAID monitoring.
IOPS refers to the number of read and write operations performed on a disk per second. Monitoring the IOPS data helps in determining whether IOPS is deteriorating slowly over time, which may suggest severe underlying problems in your RAID.
OpManager's storage monitoring capabilities help you monitor storage devices such as disk drives, controllers, virtual disk groups, and RAID groups. Learn more about how RAIDs are monitored and managed in OpManager.
The data monitored from the storage devices can be visualized in a graphical view, which helps tremendously in understanding the network. You can monitor the health and availability of a storage RAID in real time, and if a hardware or software issue arises, you will be alerted so you can rectify the problem quickly
Moreover, OpManager's detailed reports can help you quickly determine the overall health and performance of your network and network devices. In addition to RAID monitoring, OpManager offers advanced network monitoring capabilities to help ensure the optimal performance of your devices while eliminating network blind spots.