Electrical computers and digital processing systems: memory – Storage accessing and control – Specific memory composition
Reexamination Certificate
2000-07-10
2001-11-13
Yoo, Do Hyun (Department: 2187)
Electrical computers and digital processing systems: memory
Storage accessing and control
Specific memory composition
C711S100000, C711S113000, C711S114000, C711S148000, C714S006130, C707S793000
Reexamination Certificate
active
06317807
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to data storage apparatus for use in computer systems.
2. Description of the Prior Art
It is known in a computer data storage system to divide the available data storage into a plurality of physical drives, each drive providing a data storage space. A single physical drive may be partitioned to provide different spaces on the drive and/or to create “logical drives”.
It is known to allocate data to the resultant spaces by giving the spaces names such as A, B, C, D, etc and allocating data to them according to names (A, B, C, D) manually chosen using e.g. a keyboard or pointing device. This is done in DOS, WINDOWS and for networks NOVELL Netware, for example. (DOS, WINDOWS and NOVELL are TradeMarks). Such allocation of data takes no account of the need to quickly access the data with substantially equal ease of access to wherever it is stored.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided a data storage apparatus having a plurality p of data storage spaces for the storage of sets of data, and allocation means for allocating the sets of data to the p spaces, the allocation means determining for each space p an allocation factor Qp where
Qp=&Sgr;f(ai,xi)
where the xi(i=1 ton) are a predetermined set of variables which influence the ability of a space p to store a data set at the time the set is to be allocated to the space and to allow the data set to be read out, and
ai are weighting factors for weighting the variables according to a predetermined ranking of the relative importance of the variables,
the Qps of the spaces p being compared and the data being allocated to a space p in dependence upon the comparison.
In an embodiment of the invention,
Qp=&Sgr;ai (xi)
2
or &Sgr;ai (xi)
and data is allocated to the one of the spaces p having the lowest value of Qp.
xi are for example:
x
1
—measure of unused space in space p
x
2
—measure of data sets stored in space p
X
3
—measure of available channels for accessing space p
x
4
—measure of number of times a space p is scheduled for reading data out and/or writing data in.
Thus, the invention allows data to be automatically allocated amongst spaces p, by comparing the Qp's of the spaces and selecting the best (e.g. the lowest value of Qp). Thus data is allocated efficiently to the spaces and is allocated in a way maximising the efficiency of access to it.
The variable x
1
will act with a tendency to evenly distribute the amount of data amongst the spaces p.
Variable x
2
will act with a tendency to evenly distribute the number of data sets amongst the spaces p.
Variable x
3
will act to allocate data according to the access bandwidth available.
Variable X
4
will act to allocate data according to the expected usage of a space.
The weighting factors weight the variables in a predetermined ranking. The weighting factors are chosen by the system designer so that the designer can balance the influences of the various variables xi on allocation.
The invention allows, for example, data sets to be allocated to a plurality of spaces so that all data sets can be accessed efficiently from all the spaces p.
Although four particular variables x
1
to x
4
have been discussed, other variables may affect the efficiency of accessing data storage space. The present invention allows any number of variables to be taken into account.
According to another aspect of the invention, there is provided data storage apparatus comprising
a plurality
p
of data storage spaces for the storage of sets of data, and allocation means for allocating the sets of data to the
p
spaces, according to usage indices of the spaces, the indices of the usage of the spaces being indicative of the ability of the apparatus to transfer data in different modes of operation.
In a preferred embodiment of the invention the data storage apparatus accords with both of the said aspects of the invention.
The usage indices represent a numerical model of the data storage apparatus and the apparatus is controlled in accordance with that model.
The said another aspect of the invention allocates data to that one of the
p
spaces which at the time of allocation, has resources available to allow the transfer. Thus, it allows data to be transferred to a space
p
in accordance with the value Qp, only if that space
p
has the resources available to allow the transfer.
In one example of the invention, the data is video data. In that example the modes of use include for example, idle, (i.e. unused), record, and playback. Playback may be at various speeds, e.g. 1×, 2×, 4× normal speed. Other modes discussed hereinafter may exist.
Each space p may have a plurality of input/output channels, each of fixed bandwidth.
Idle makes no use of the space and of the bandwidth of the channels.
Playback may use one or more output channel, with 4×playback using the entire bandwidth of an output channel, slower playback using less. Record similarly uses at least one input channel.
Some modes of operation may use two or more channels. Furthermore, one or more channels may be defective.
The useage indices may be used to determine which combinations of modes of operation of a storage space can occur simultaneously. For that purpose the apparatus comprises scheduling means for storing a schedule of transfers of sets of data to/from the spaces p, the transferring means transferring data to and/or from a space p at a particular time if, the sums of corresponding useage indices associated with the transfers scheduled for that particular time are all less than respective predetermined values.
REFERENCES:
patent: 4130870 (1978-12-01), Schneider
patent: 4435762 (1984-03-01), Millligan et al.
patent: 4638424 (1987-01-01), Beglin et al.
patent: 5345584 (1994-09-01), Hill
patent: 5506986 (1996-04-01), Healy
patent: 5537534 (1996-07-01), Voigt et al.
patent: 5579507 (1996-11-01), Hosouchi et al.
patent: 5657468 (1997-08-01), Stallmo et al.
patent: 5659704 (1997-08-01), Burkes et al.
patent: 5675726 (1997-10-01), Hohenstein et al.
patent: 5732402 (1998-03-01), Lehman
patent: 5742792 (1998-04-01), Yanai et al.
patent: 5835959 (1998-11-01), McCool et al.
patent: 5889935 (1999-03-01), Ofek et al.
patent: 5901327 (1999-05-01), Ofek
Cox Penelope Susan
Dorricott Martin Rex
Shepherd David Colin Charles
Chang Dexter T.
Frommer William S.
Frommer & Lawrence & Haug LLP
Namazi Mehdi
Sony Corporation
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