Access speed of RAID controllers

[Lalana]

I am having an idea that an expensive storage RAID controller with an onboard cache are often misconfigured and therefore does not use its full performance. But came to know that a few simple steps can be such a storage system with write operations much faster. So, I am here to check some hints from you members. What you people will advise me to do.?

[Taipai]

Many high-quality RAID controllers with onboard cache, have two strategies for data from the operating system on the disk to write: Write Back and Write Through. When write-back sends the RAID controller a final confirmation command to the operating system when the buffer memory of the controller to write data to the hard drive has received from the system. The controller keeps the information as long in the cache until the controller finds a suitable time to transfer the data to the hard disk. This comes at a time when the system resources are not fully stressed, so that strategy, the write performance improved significantly. Otherwise behaves the write-through strategy. This sends a final confirmation to write only to the operating system when the data has been written safely to disk. Why does the transfer process or system performance, because the information directly without buffering, regardless of current system resources, disk can be written.

[DayanandPatil]

The write-back option can be used in most RAID controllers with cache in the controller setup to activate. In the setup menu of the adapter you get, in which the user enters during the initialization of the storage adapter at system boot, the keyboard shortcut for calling the setup function. In general, it is (depending on the manufacturer) Write-Back and Write-through option is the current controllers Ctrl G or Ctrl R. However, the write-back method also has disadvantages. If a fault in the power supply on, are also important data that is not from the cache controller on the disk were written, is permanently lost. It is therefore advisable to use the optional battery backup most of the cache controller.

[Mentos]

I would like to tell you that information (tips) provided by the above members ("Taipai" & "DayanandPatil") applies to all RAID controller with cache functionality (with and without battery pack) and appropriate firmware option. With Redundant Array of Independent Disks (RAID), multiple independent hard drives connected together to form a large logical drive. Not only data stored on this array, but also "redundant information" was added. This redundant information, the data itself (mirroring) or parity data from multiple data blocks in RAID 3, 4, or 5 charges.

[Preetish]

The operating system like Windows or Unix takes no longer to the individual hard drives, but instead on the array. Increasing the availability is the primary purpose of the raid. RAID prevents downtime in the event of a hard drive failure. However, it can not restore data that was deleted by users or destroyed by an event such as theft or fire. Therefore one always needs a backup to before these events to protect the system, even if a RAID system is installed. In principle, technology can be the RAID to SCSI and SAS or SATA systems apply equally. It is however acknowledged that it is for SCSI and SAS / SATA storage architecture for two is completely different.