What is MAID?

Massive Array of Idle Disks (MAID) refers to a computer system that uses hundreds or even thousands of disk drives for near-line storage. Near line storage falls between online rapid access or disk storage and off line tape storage. Using a MAID system allows the amount of information being stored to be relatively unlimited, while keeping access to the information stored there as fast as possible. Using MAID storage is a way for organizations to limit the retrieval of information once it has been stored. The concept supports a write once, read occasionally methodology where the information moved into the MAID system is not accessed every day. Disk drive and storage technology have been significantly improved over the past few years. These improvements in disk drives, such as the introduction of Serial ATA (SATA) drives which are built to be powered on and off as needed has reduced the amount of power needed to maintain and support MAID storage systems. The SATA drives can spin up ...  more

MAID stands for Massive Array of Idle Disk. Essentially, it allows for incredibly dense packaging of data.MAID is a perfect fit for what is considered 'persistent' data. That is, data that is written once and accessed occasionally. MAID is not high performance, Tier One storage but ideally suited for Tier Three and below. With de-duplication and replication now available, it becomes a compelling replacement for tape. Check out Copan Systems.

At first, i dont really think this technology justify companies, that do MAID for a living. Its too easy to integrate this feature in other system. At the end MAID is just hard disk power management in action. When a disk isnt used, switch it off. Just in the case you need data from them, switch them on. As it would be senseless to switch off a disk after two seconds just to reactivate it 2 seconds later (or it wouldnt switch the disk off at all in the case you choosed a longer interval) the concept of cache drives was introduced to the concept MAID. This drives cache the most often requested blocks. In opposition to the MAID drives, this drives are active at any time. As these cache drives should satisfy a large amount of disk requestsm, the MAID drives are not activated, the power management of the hard disk can keep them idle. At the end, this is all. Well ... then i started to think about it and came to an interesting conclusion. Every OpenSolaris user has the components to build ...  more