Dynamic Runtime Attributes
There are frequently field issues where customers must know which Initiator is holding a reservation in a drive or preventing the media from being unloaded. Also, they must correlate which drive special file name is used for the drive (such as rmt2). Sometimes this issue occurs over transport bridges and translators, losing any transport identifiers to help in this effort. LTO5, 3592 E07 (Jag 4) and later physical tape drives support attributes that are set to the drive dynamically by a host. This function is called Dynamic Runtime Attributes (DRA).
This feature is enabled by default. The attributes are set in the drive by the host during open, close, device reset, and data path change only. If there is a problem with sending the attributes to the drive, the error is ignored and not returned to the application.
There is no ioctl in the IBM® tape drivers to retrieve the dynamic runtime attributes but is an upcoming command on ITDT. The attributes can also be retrieved through a pass through ioctl to issue Read Dynamic Runtime Attributes SCSI command (see applicable IBM Tape Drive SCSI Reference). See the host platform section for any special information that pertains to the driver that concerns DRA. If there is a question whether your driver level supports DRA, see the fixlist that comes with your driver to see whether it was added. Updates are also required with the drive firmware.