Command Specifications

Together with the RELEASE command, this command controls exclusive access to the logical unit (IDD) under a multi-initiator environment.

The IDD is reserved by this command for the INIT which issued this command or for some other SCSI device specified in the CDB.

The INIT which issues this command must notify the IDD of its own SCSI ID when the SELECTION phase is executed.. When the INIT's ID cannot be specified, this command is terminated with a CHECK CONDITION status (ILLEGAL REQUEST [=5] / Initiator's SCSI ID not identified [=90-00]) without being executed. Also, the values specified in bytes 2 to 4 of the CDB have no meaning and are disregarded, but it is preferable that the INIT specify X '00' in these bytes.

(1)Logical unit reserve function

This command reserves the entire IDD (logical unit) for use as a special SCSI device. The reserve state established by this command is maintained until any one of the following conditions occurs.

1)The reserve condition is changed by the INIT that issued this command (Superseding Reserve).

2)Reserve is released by a RELEASE command from the INIT that issued this command.

3)A TARGET RESET message from any INIT.

4)A RESET condition.

5)Switching the IDD's power off or on.

When an IDD is reserved for any SCSI device, if this command is issued by an INIT that doesn't have the "Reserve Right" for that IDD, this command is terminated with a RESERVATION CONFLICT status. See item (3) concerning the "Reserve Right."

After the Reserved status is established, a command issued by an INIT other than the SCSI device that reserved the IDD is rejected, except an INQUIRY, REQUEST SENSE or RELEASE command, and a RESERVATION CONFLICT status is reported to the INIT that issued that command. The INQUIRY and REQUEST SENSE commands are executed normally even when the IDD is reserved for use by another SCSI device. Also, a RELEASE command is terminated with a GOOD status, but the release operation specified in a RELEASE command issued to the IDD by a SCSI device which does not have the Reserve Right is disregarded.

(2)Reserve right and third party reserve function

If the "3rd Pty" bit in byte 1 of the CDB is "0," the IDD is reserved by the INIT which issued this command and that INIT has the Reserve right for the IDD.

If the "3rd Pty" bit is "1," the third party reserve function is specified. An INIT which specifies the third party reserve function and issues this command can reserve the IDD for use by another SCSI device. In this case, this command reserves the IDD for the SCSI device (called the third party device) with the SCSI ID specified in the "3rd Pty Dev ID" field in byte 1 of the CDB. Even if the IDD is reserved for another SCSI device using the third party reserve function the reserve right for that ID resides with the INIT that issued this command. Therefore, in order to release that reserve state, it is necessary for the INIT that issued this command to issue a RELEASE command (shown in Section 3.1.13) with the third party release function specified. Also, the conditions for maintaining the reserve state established by the third party reserve function are the same as in the case where the third party reserve function is not used. (See item (1).)

Please note that since only 3 bits are defined for the "3rd Pty Dev ID" field, this command is valid for the third party reserve function with respect to only SCSI devices with SCSI ID 7 to 0.

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Fujitsu MAP3367, MAP3147, MAS3735, MAP3735, MAS3367 specifications Command Specifications
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MAP3735, MAP3147, MAS3367, MAP3367, MAS3735 specifications

Fujitsu, a renowned leader in technology and innovation, has developed a variety of reliable hard disk drives (HDDs) that cater to a wide range of data storage needs. Among these, the MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series stand out for their advanced features and exceptional performance.

The MAS3735 is a high-capacity enterprise-class drive that boasts a storage capacity of up to 300 GB. Its 10,000 RPM spindle speed ensures rapid data retrieval and efficient performance, making it ideal for data-intensive applications. It utilizes a Serial Attach SCSI (SAS) interface, which allows for improved data transfer rates and increased reliability compared to traditional SATA drives. The drive is designed with advanced technologies such as error recovery and data integrity features, ensuring the safety and security of critical data.

Similarly, the MAP3367 and MAS3367 models are geared towards both enterprise and mid-range server environments, providing a storage capacity of up to 300 GB as well. These drives also operate at a spindle speed of 15,000 RPM, offering swift access times that enhance overall system performance. The MAP3367 employs the Ultra 320 SCSI interface, allowing for significant bandwidth and ensuring data is transmitted efficiently.

On the other hand, both MAP3147 and MAP3735 models provide versatile solutions for various applications, supporting capacities from 36 GB to 147 GB. The MAP3147, with its 10,000 RPM speed, is optimized for workloads requiring quick access and high throughput, making it suitable for transactional systems and enterprise applications. The MAP3735, while offering comparable capacity, emphasizes exceptional reliability and durability, which is crucial for environments that involve heavy data loads.

All these Fujitsu HDDs are characterized by their robust construction, reliability, and efficiency. They are built to withstand heavy workloads and are equipped with features like advanced thermal management and acoustic noise reduction, ensuring they operate effectively in data center environments.

In conclusion, Fujitsu's MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series HDDs are designed for high performance and reliability, catering to both enterprise and mid-range environments. Their advanced features make them a strong choice for businesses looking to enhance their storage solutions while maintaining data integrity and system performance.
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