I/O Performance: Slightly lower write performance with nearly double the read performance.Capacity: VD = (C * n) / n | VirtualDrive = ( Capacity of one disk * number of disks ) / number of disks.In these cases, write performance will slightly degrade as the number of disks increase and the read performance will scale with the number of disks. NOTE: While most hardware based RAID controllers typically only support two disks in a RAID 1 array, some controllers and software RAID systems may support more than two disks. Because the data is mirrored on both disks in the array, either one of the disks can fail, as log as one remains functional, without causing the array to fail. This is because when the RAID controller needs to write data it has to do so on both disks, however, when it needs to read data it can simultaneously fetch two different reads from either disk since the data set on both disks is mirrored. Because of this, the I/O performance characteristics will have slightly lower write performance compared to a single disk, while read performance will be nearly double that of a single disk. Each time a data block is written to the storage subsystem, your RAID controller will write that same data block on both disks, providing fault tolerance should one of the disks fail. Summary: RAID 1 mirrors data at the block level on two disks.Fault Tolerance: None, increased risk of failure that scales with number of disks in the array.I/O Performance: Greatly improved read and write performance.Capacity: VD = (C * n) | VirtualDisk = ( Capacity of one disk * number of disks ).We do not recommend using a RAID 0 for production systems. As such, the risk of data loss due to a drive fault will also scale with the number of disks within the array. Because RAID 0 spreads storage blocks across all of the disks in the array, any disk failure will result in the entire array being lost. A RAID 0 can contain two or more disks, with the maximum number being limited based on the number of disks supported by your RAID controller and available drive bays for your server. As such, the performance will tend to scale with the number of disks within the array. This is due to the ability of the array to simultaneously read or write a block to each of the disks in the array. Because the data is striped across multiple disks, you will see improved read and write performance, especially for larger files. Summary: RAID 0 stripes data at the block level across each of the disks in the array.Read on for a more detailed version of the pros and cons of each. Some common RAID levels include RAID 0, RAID 1, RAID 5, RAID 10. Not all RAID configurations are created equal in terms of redundancy, speed, or disk size. Depending on the complexity of your RAID configuration, performance could be an issue if you are using software RAID. Hardware RAID provides more flexibility via more configuration options and frees you from the limitations of a software RAID. However, you are restricted to the RAID levels your OS can support. This is the cheaper option all you need to do is connect the drives and configure the OS. Software RAID: When drives are connected to the server motherboard without a RAID controller, the configuration is managed by the Operating System’s software. This provides optimal performance, as the processing is handled by the RAID card rather than the server, providing less strain when writing backups and restoring data. Hardware RAID: With a hardware RAID setup, the drives connect to a RAID controller card inserted in the server’s motherboard. There are two types of RAID, each with their advantages and disadvantages. With RAID installed, the drive would be replaced, and you could rebuild and sync the RAID from the old drive to the new drive, and there would also be no backup restoration required. Then backups need to be restored all this could take 5 or more hours easy. Without RAID installed, your server and business will suffer downtime while the drive is being reconfigured and replaced. Here’s the nightmare scenario: Your hard drive fails (hard drives always fail, just a matter of when, let’s just hope it’s not Cyber Monday). If staying online is essential, RAID is your failover insurance. Whether to deploy RAID depends mostly on how important uptime is to your operations. Let’s go over some common questions regarding RAID and see what the best RAID configuration is for your server.įirst of all, ask yourself if your server needs a RAID set-up. RAID (Redundant Array of Inexpensive Disks) is a data storage virtualization technology that combines multiple disk drives into a single logical unit for faster performance, better hardware failover, and improved disk Input/Output reliability.
0 Comments
Leave a Reply. |