JPH0281349A - Automatic library storage system - Google Patents

Abstract

PURPOSE:To determine a deck optimum in performance by informing an automatical library memory of a memory driving group, which becomes the candidate of selection, determining the optimum driving out of a candidate driving group with an automatic library memory and informing a host system of the driving number. CONSTITUTION:A host program 3, at the time of selecting a deck, transfers a deck number which goes to a candidate as the parameter of a command for an automatic library memory 13. The automatic library memory 13 side selects the optimum deck based on the characteristic value of hardware out of the candidate deck and informs a host program 3 of the number of the selected deck as the data of the command from the host program 3. The host program 3 executes the deck selection based on the data. Consequently, the soft program, even when the hardware characteristic is not known, can select the deck to process the exchanging medium. Thus, the processing performance of a automatical library memory can be increased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a storage device for a computer system, and in particular to an automatic library that stores a large amount of replaceable storage media and automatically exchanges them for reading and writing. A suitable means for improving the performance of a storage device is provided.

[Conventional technology]

There have long been a number of devices that store large amounts of exchange media (especially magnetic tapes) and automatically mount and demount the exchange media on data read/write devices (deck units) as instructed by the computer system. , for example, the document “Electronic Corporation Research and Practical Application Report Vol. 35 No. 7 P697-7
11" contains an example of magnetic tape. Conventionally, when operating such an automatic library storage device in a computer system, the host computer informs the automatic library storage device of the volume name of the medium to be moved or the location of the cell that stores the medium, and the location of the cell that stores the medium. Indicates the number of the deck that will process the media. The library device operates according to its instructions. The travel time of the cartridge is uniquely determined. On the other hand, the host computer determines which deck to use when the user specifies the media that the user wants to process. A device group is specified, and one device is selected from decks in the device group that are not used by other users according to an algorithm programmed into the host computer.

In this case, the algorithm may be in ascending order,
The selection is based on general information that the host computer program can know, such as the fact that it has been a long time since it was last used.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, deck selection is determined independently of the physical characteristics of the hardware, that is, the automatic library storage device, so it is not necessarily optimal from a performance standpoint. In other words, when mounting a medium on one of several decks, the difference between selecting a deck far from the medium and selecting a nearby deck is It is better to select a nearby deck that has a short travel distance, but this cannot be done unless the host software has accurate information on the physical location of the deck and media. Another problem is that the host software must be changed every time the physical characteristics of the device change (for example, whether the medium is a magnetic tape or an optical disk). An object of the present invention is to provide a means for host software to determine the optimal deck in terms of performance without knowing the physical characteristics of the hardware when selecting a deck for processing media.

[Means to solve the problem]

The purpose of the above is that when the host software determines which deck to use from among multiple decks, the hardware determines the numbers of the multiple decks, the volume name of the target exchange medium, or the location of the cell that stores the medium. This is achieved by notifying the host software, the hardware determining the optimal deck from its own physical information, and replying the determined deck number to the host software.

[Effect]

When selecting a deck, the host program transfers the candidate deck number as a parameter of a command to the automatic library storage device. The automatic library storage device side selects an optimal deck from among the candidate decks based on the characteristic values of the hardware, and notifies the host program of the number of the selected deck as command data from the host program. The host program makes deck selection based on this data, so the software program can select a deck to process the exchange medium without knowing the characteristics of the hardware.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Figure 1 shows the present invention on a cartridge-type magnetic tape (hereinafter referred to as MT).
A conceptual diagram of the application to an automatic library system (abbreviated as ) is shown.

Consider a case where a certain job program is run on the host computer 1. Assuming that this job uses magnetic tape volume A, this is specified by the user (job program creator) using job control statement 2. At this time, the user specifies which MTU group (MTU group) is to be used at the same time. Now automatic library storage device 1
Magnetic tape opening unit (MTU) 14 to 17 in 2
For example, if the MTU group name "LMT" is given to "LMT", the user will specify "LMT 11". Program 4
Allocates MTU for volume A using job control statement 2 before executing the user program, but
The allocation program 5 is made to do this. This is commonly done in conventional computer systems and is a known technique. Allocation program 5 is MT
Since "LMT" is specified as the U group name,
Select the deck to be used from MTU #0 to #3 (14 to 17). Now, if MTU#O; 14 is used by another job, the remaining MTU#1; 15. M
TU#2; 16. MTU #3; 17 is the target of allocation. In the conventional technology, which MTU is selected from among these three decks is determined according to a certain algorithm.
For example, allocation was done according to an algorithm that started with the lowest number. In this case, assuming that the selection starts from the smallest number, MTU #1 i 15 will be selected. This is notified to the execution control program 6, and the execution control program is sent to the magnetic tape controller (MTC).
;23, a read/write command for cartridge A to MTU #1;15 is issued. On the other hand, the automatic library storage device 12 (hereinafter abbreviated as ALS) stores cartridge A;18 corresponding to volume A in MTU #1.
When instructed by the mount command list 10 from the host program 3 to mount the cartridge A 15 on the cell block 20 , the accessor robot 21 moves on the rail 22 and picks up the cartridge A 18 located at the coordinate XA in the cell block 20 . , move the rail 22 again and get the coordinate Xu
Cartridge A; 18 in MTU #1; 15 located at □
mount.

This is also conventional technology. In this case, if the movement distance of the accessor robot 21 is short, the movement time will be short and the performance will be improved. Therefore, in this case MTU
#1; From 15, coordinate X. .

It is preferable to select MTU #3; 17 located at , since it is closer to the position of cartridge A; 18. This embodiment makes this possible. That is, when selecting a device, the allocation program 5 sends a 5END MTU CANDIDATE command (hereinafter abbreviated as SMC command) to the automatic library controller (ALC) 13, which is one of the components of the ALS1 2, via the channel interface A7. Issue. This command sends the name of the cartridge to be used, its location, and the MTU deck number that is a candidate for two selections. It is not necessarily necessary to send both the name and location of the cartridge; either one is fine.

In other words, ALSl2 can be operated without knowing the name of the cartridge as long as the location is known, and
This is because if the memory 21 has a correspondence table between the cartridge name and the location in the LS12, the location can be determined even if only the cartridge name is received. In Ikiko's example, the cartridge name is A.

Existence position XA and selection candidate MTU deck numbers #1, 2
．． 3 is sent. The ALCi 13 stores the AL in the memory 21.
S; Existence position coordinates of all MTU decks in 12 XIJ
It remembers O~XUa. The MTU numbers just sent are 1, 2.3, so the coordinates of these MTUs are XUL+
XU,, It is the locus where Xus and cartridge A exist.
xA, and determine the MTU with the smallest value. In this case, the coordinates of MTU #3 are closest to the coordinates of the cell where cartridge A exists, so MTU #3
is determined.

ALS 12 sends this result to 5ENS issued by O8;3.
The optimal MTU list 11 is notified as data for the E OPTIMAL MTU command. This data includes the cartridge name and determined MTU number. In this case, cartridge name A and MTU number 3 are sent. The allocation program 5, which forms part of the host program (O5);3, learns the optimum MTU number from this data and selects this MTU as the MTU for processing the target volume. That is, in this case, MTU #3 is selected as the MTU that processes volume A (cartridge A; 18). After this, the method of instructing mounting and the method of reading and writing volume A are the same as those described in the prior art.

(Effects of the Invention) According to the present invention, the host program (O8) can select the most suitable storage drive for processing the exchange medium without knowing the characteristics of the hardware. In addition to being able to improve performance, this also has the effect that the host program (OS) does not need to be changed even if the hardware structure or type of exchange medium changes.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a system showing an embodiment of the present invention.

Claims (1)

[Claims] 1. A plurality of exchange media, a cell that stores the exchange media, a plurality of storage drives that read and write data from and to the exchange media, a control device that controls the storage drives, and a controller that controls the exchange media between the cells and the storage drives. An automatic library storage device consisting of an accessor robot that carries, mounts, and demounts and a library control device that controls the accessor robot, and provides instructions for mounting/demounting necessary exchange media and reading/writing data to the automatic library device. In a computer system comprising a host system, when the host system selects a storage drive for processing a requested exchange medium, it notifies an automatic library storage device of a group of storage drives that are candidates for selection, and performs automatic library storage. An automatic library storage system characterized in that a device selects a storage drive to be used by determining an optimal drive from a group of candidate drives and notifying a host system of the drive number.