Backup apparatus, backup method and backup program

A backup method using an address conversion table for storing, in correspondence with each other, a logical address designated by a host system and a physical address indicating a data storage position in a copy destination volume, the method comprising:

• setting sequential data count information indicating the number of data blocks in a sequence in the physical address;
• reading the data block, upon receiving a read request, in the address conversion table corresponding to a leading logical address among the logical addresses requested to be read, and acquiring the sequential data count information set in the address conversion table;
• and
• reading a physical volume corresponding to the physical addresses in a sequence in accordance with the sequential data count information acquired.

A computer-readable recording medium encoded with a backup program using an address conversion table for storing, in correspondence with each other, a logical address designated by a host system and a physical address indicating a data storage position in a copy destination volume, and containing instructions executable on a computer, the program causing the computer to execute:

• setting, in the address conversion table, sequential data count information indicating the number of the data blocks in a sequence in the physical address;
• reading the data block, upon receiving a read request, in the address conversion table corresponding to a leading logical address among the logical addresses requested to be read, and acquiring the sequential data count information set in the address conversion table;
• and
• reading a physical volume corresponding to physical addresses in a sequence in accordance with the sequential data count information acquired.