Massive array of idle disks

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A massive array of idle disks ( MAID for short ) is a disk array in which individual hard disks can be operated to save energy. This is done, for example, by parking the read head or by reducing the speed . The advantage of this technology is that the energy consumption (and thus also the heat output) drops considerably, which is particularly interesting in the context of Green IT . Typical areas of application are applications that write data to a limited area and then read it only rarely, such as virtual tape libraries or systems for electronic archiving .

There are typically three MAID levels

  • Level 1: Park the reading head
  • Level 2: Park the read head and reduce the speed of the hard disk
  • Level 3: Stop the hard disk

Since a hard disk in a MAID is normally only switched on when data stored on it has to be read, problems can arise during long-term operation (e.g. solidification of the lubricant in the bearings). This is counteracted by storing the runtimes of the individual hard disks in a central location and, if necessary, briefly booting the hard disks that have not been running for a long time in a phase with low load.

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