System for and method of accessing blocks on a storage medium

A system for periodically writing blocks of data to a storage medium, whereby the blocks are received in the form of streams, wherein the blocks of data are stored into a file comprising logically successive clusters, a cluster having a cluster size C and having physically successive storage sectors for storing the data, the system comprising:

• admission control means for controlling the admission of a new stream having a maximum bit rate cmax, and
• write means for in a period of maximum duration P storing blocks of data to the storage medium for respective ones of the streams,
• wherein the admission control means is arranged:
• to determine a minimal block size Blower for the blocks for the new stream whereby a block of size Blower is sufficiently large to store data received at rate cmax during a period of length P,
• to determine the number of times k a block of size Blower fits in the cluster of size C, to determine for k blocks to be used for writing to the cluster a respective block size by evenly partitioning the cluster size C into the k block sizes so as arrange that the cluster can be completely written by means of the k blocks, and to determine the minimal block size Blower according to the following equation:
• Blower=P·cmax.

Method of periodically fetching blocks of data from a file on a storage medium and supplying the blocks in the form of streams, wherein the blocks of data are fetched from a file comprising logically successive clusters, a cluster having a cluster size C and having physically successive storage sectors for holding the data, the method comprising the steps of:

• controlling the admission of a new stream having a maximum bit rate cmax, and
• periodically fetching blocks of data from the storage medium for respective ones of the streams, a period having a maximum duration P,
• whereby controlling the admission includes:
• determining a minimal block size Blower for the blocks for the new stream whereby a block of size Blower is sufficiently large to sustain consumption at rate cmax during a period of length P,
• determining the number of times k a block of size Blower fits in the cluster of size C, determining for k blocks to be used for reading the cluster a respective block size by evenly partitioning the cluster size C into the k block sizes so as to arrange that the cluster can be completely read by means of the k blocks, and determining the minimal block size Blower according to the following equation:
• Blower=P·cmax.

Method of periodically writing blocks of data to a file on a storage medium, whereby the blocks are received in the form of streams and whereby the blocks of data are stored into a file comprising logically successive clusters, a cluster having a cluster size C and having physically successive storage sectors for storing the data, the method comprising the steps of:

• controlling the admission of a new stream having a maximum bit rate cmax, and
• periodically storing blocks of data to the storage medium for respective ones of the streams, a period having a maximum duration P,
• whereby controlling the admission includes:
• determining a minimal block size Blower for the blocks for the new stream whereby a block of size Blower is sufficiently large to store data received at rate cmax during a period of length P,
• determining the number of times k a block of size Blower fits in the cluster of size C,
• determining for k blocks to be used for writing to the cluster a respective block size by evenly partitioning the cluster size C into the k block sizes so as arrange that the cluster can be completely written by means of the k blocks, and determining the minimal block size Blower according to the following equation:
• Blower=P·cmax.