ODM attributes and configuring persistent reserve support

Edit online

Two new ODM attributes are added for PR (Persistent Reservation) support:
  • reserve_type
  • reserve_key
The reserve type attribute determines the type of reservation that the device driver uses for the device. The values can be reserve_6, which is the default for the device driver or persistent. This attribute can be set by either using the AIX SMIT menu to Change/Show Characteristics of a Tape Drive or from a command line with the AIX® command
chdev –l rmtx –a reserve_type=persistent or –a reserve_type=reserve_6
The reserve_key attribute is used to optionally set a user-defined host reservation key for the device when the reserve_type is set to persistent. The default for this attribute is blank (NULL). The default uses a device driver unique host reservation key that is generated for the device. This attribute can be set by either using the AIX SMIT menu to Change/Show Characteristics of a Tape Drive or from a command line with the AIX command
chdev –l rmtx –a reserve_key=key
The key value can be specified as a 1-8 character ASCII alphanumeric key or a 1-16 hexadecimal key that has the format 0xkey. If fewer than 8 characters are used for an ASCII key such as hostA, the remaining characters are set to 0x00 (NULL).
Note: If the Data Path Failover (DPF) feature is enabled for a logical device by setting the alternate_pathing attribute to yes, the configuration reserve_type attribute is not used and the device driver uses persistent reservation. Either the user-defined reserve_key value or if not defined the default device driver host reservation key is used.