4.1 Control/Sense Commands

4.1.18 PERSISTENT RESERVE OUT (5F)

 

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This command is used for reserving so that the particular initiator can use the logical unit exclusively or share with others. The command shall be used in conjunction with the PERSISTENT RESERVE IN command and shall have no relevance to the RESERVE and RELEASE commands.

By using the reservation key defined by the INIT, PERSISTENT RESERVATION can be used to identify initiators that execute any of the Service Actions of the PERSITENT RESERVE OUT commands and that conflict with a reserve condition established by the RESERVE command. An INIT can check to see which INITs hold conflicting or illegal reserve conditions by using the PERSISTENT RESERVE IN command and, if necessary, an INIT can make new reserve conditions preempt these reserve conditions by using the PERSISTENT RESERVE OUT command.

Since set reserve conditions cannot be reset by processing such as TARGET RESET task, PERSISTENT RESERVATION can be used to have multiple INITs share a device. The PERSISTENT RESERVE OUT and PERSISTENT RESERVE IN commands provide a fundamental mechanism to analyze reserve conditions that change dynamically in a multi-initiator system using multi-port TARGs. It becomes possible to identify whether TARGs have particular reserve conditions, and to remove reserve conditions from INITs that have errors or are uncooperative.

If the reserve condition implemented with the RESERVE/RESERVE EXTENDED command is held when a drive receives this command, this command is rejected with the report of the RESERVATION CONFLICT status.

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Fujitsu MBC2036RC, MBC2073RC, MBA3300RC, MBA3147RC, MBA3073RC specifications Persistent Reserve OUT 5F