International Business Machines Corporation

Warren B Harding

Richard Anthony Ripberger

Scott Milton Fry

Jerry Wayne Pence

Wayne Erwin Rhoten

Vincent K Allen

Horace T Tang

Robert G Long

Connie M Clark

Robert Douglas Tennison

William O Vomaska

Michelle K Blount

An adaptive data transfer channel providing means for a data management access method (AM) to define the channel subsystem data block transfer size and to transfer an extended data block (EDB) by a single channel transfer command to avoid repeated channel command word (CCW) command decode and status presentation operations. The adaptive scheme of this invention is transparent to the user and downwardly compatible with existing data record storage formats because it is independent of the user application program. The host software in the central processing complex (CPC) tests the peripheral data storage device (PDSD) to ensure compatibility with the EDB CCWs before selecting the channel program (CP) to be used for data block transfer in the subchannel. In the EDB format, the PDSD microcode permits the accumulation of logical data blocks (LDBs) from storage to form a single large EDB before transfer to the CPC responsive to a single transfer command. Conversely, the CPC can transfer a single EDB to the PDSD where it is parsed to form data records in an existing data record storage format, thus ensuring complete downward compatibility with existing data record storage formats.

Extension of data block capability in a data transfer channel

Adaptive data transfer channel employing extended data block capability

A method for managing data in a data storage hierarchy, and a data storage hierarchy suitable therefor, is disclosed. The data storage hierarchy includes an optical library and separate manually operated shelf storage. The optical library includes at least one optical disk drive and a plurality of storage cells for the storage of optical disks. The optical library also includes automatic means for transferring optical disks from the storage cells to the optical disk drives in the library. The host processor, upon determining that particular data is required to be stored in the optical library, first checks to determine if the optical disks in the optical library currently have the capacity for the storage of such data. If the capacity exists in the optical library there is no problem and the data is stored therein. If the optical library does not have the required capacity, or if the system operator so requires, the optical disk in the optical library which has least recently been mounted on an optical disk drive therein is destaged from the optical library to the manually operated shelf storage. Another disk may then be fed into the optical library for the storage of the data required therein.

Method of managing data in a data storage hierarchy and a data storage

Image data objects are accumulated in a relatively rapid access data buffer, such as a combination of main memory and a rapid access magnetic DASD. An optical disk recorder having a record medium with a plurality of addressable sectors each capable of storing a predetermined number of the VTOC entries receives the accumulated data objects along with the associated VTOC entries in a single access whenever the number of accumulated data objects is an inegral number of said predetermined number. A lower threshold for a minimal number of data bytes of the accumulated data objects may be required before such single access data recording operation is effected. An upper threshold of number of data bytes in the accumulated objects is also provided for causing the single access data transfer irrespective of the number of objects being an integral number of said predetermined number. The invention is advantageously practiced with a write-once, read-many record medium.

Batching data objects for recording on optical disks with maximum object

A peripheral data storage hierarchy includes three storage levels. The top storage level is a fast accessing direct access storage device(s), such as magnetic disk drives. The intermediate level is an automatic warehouse type library, storing a large plurality of optical disks, which are automatically transferred between storage cells of the library and optical disk drives operatively connected to the host processor. The bottom level of the storage hierarchy includes one or more stand-alone optical disk drives and a shelf unit. Personnel manually carry the optical disks between the stand-alone drives and the shelf unit upon mount and demount commands received from the host processor. The intermediate library level uses the same type of optical disk as used in the bottom level of the data storage hierarchy. An I/O station in each of the automatic libraries enables manual access to the optical disk for transferring the optical disks between the intermediate and bottom levels. Preferably, the transfer is only from the intermediate level to the bottom level. Access to named storage objects in disks stored in the bottom level are through the stand-alone drives. A host processor has an independent access path to each level of the data storage hierarchy. A directory and other data structures indicate the number of copies made of each named data object and the location of such copies, such that the host processor 10 can independently access a copy from any level of the data storage hierarchy.

Multi-level peripheral data storage hierarchy with independent access to

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Tucson, AZ, United States of America

Warren B Harding