SCSI Primary Commands - 2.pdf

T10/1236-D Revision 20 18 July 20017.10.4.3 Persistent Reservations TypeThe value in the TYPE field shall specify the characteristics of the persistent reservation being established for alldata blocks within the element or within the logical unit. Table 72 defines the characteristics of the different typevalues. For each persistent reservation type, table 72 lists code value and describes the required device serversupport. In table 72, the description of required device server support is divided into two paragraphs. The firstparagraph defines the required handling for read operations. The second paragraph defines the required handlingfor write operations.Code Name DescriptionTable 72 — Persistent reservation type codes0h1h2h3h4h5h6h7h - FhWriteExclusiveExclusiveAccessWriteExclusive –RegistrantsOnlyExclusiveAccess –RegistrantsOnlyReservedObsoleteReads Shared: Any application client on any initiator may initiate tasks that requesttransfers from the storage medium or cache of the logical unit to the initiator.Writes Exclusive: Any task from any initiator other than the initiator holding thepersistent reservation that requests a transfer from the initiator to the storagemedium or cache of the logical unit shall be terminated with RESERVATIONCONFLICT status.ObsoleteReads Exclusive: Any task from any initiator other than the initiator holding thepersistent reservation that requests a transfer from the storage medium or cache ofthe logical unit to the initiator shall be terminated with RESERVATION CONFLICTstatus.Writes Exclusive: Any task from any initiator other than the initiator holding thepersistent reservation that requests a transfer from the initiator to the storagemedium or cache of the logical unit shall be terminated with RESERVATIONCONFLICT status.ObsoleteReads Shared: Any application client on any initiator may initiate tasks that requesttransfers from the storage medium or cache of the logical unit to the initiator.Writes Exclusive: A task that requests a transfer to the storage medium or cacheof the logical unit from an initiator that is not currently registered with the deviceserver shall be terminated with RESERVATION CONFLICT status.Reads Exclusive: A task that requests a transfer from the storage medium orcache of the logical unit to an initiator that is not currently registered with the deviceserver shall be terminated with RESERVATION CONFLICT status.Writes Exclusive: A task that requests a transfer to the storage medium or cacheof the logical unit from an initiator that is not currently registered with the deviceserver shall be terminated with RESERVATION CONFLICT status.108 dpANS SCSI Primary Commands - 2 (SPC-2)