1.1 Standard Features
(7)Cache feature
After executing the READ command, the IDD reads automatically and stores (prefetches) the subsequent data blocks into the data buffer
The high speed sequential data access can be achieved by transferring the data from the data buffer without reaccessing the disk in case the subsequent command requests the prefetched data blocks.
The Write Cache feature is supported. When this feature is enabled, the status report is issued without waiting for completion of write processing to disk media, thereby enabling high speed write processing.
When Write Cache is enabled, you should ensure that the cached data is surely flushed to the disc media before you turn off the drive's power.
To ensure it, you should issue either the SYNCHRONIZE CACHE command or the STOP UNIT command with specifying “0” to the Immediate bit, and then confirm that the command is surely terminated with the GOOD STATUS.
(8)Command queuing feature
The IDD can queue maximum 128 commands, and optimizes the issuing order of queued commands by the reordering function. This feature realizes the high speed processing.
(9)Reserve and release functions
The IDD can be accessed exclusively in the
(10)Enclosure service function
The IDD supports the enclosure service interface (ESI), which complies with
(11)Error recovery
The IDD can try to recover from errors in Fibre Channel Loop or the disk drive using its powerful retry processing. If a recoverable data check occurs,
