Abstract:

Under the technique of Hierarchical Storage Management (HSM), this paper discusses optimal times of data transfers for enormous data within a server system. First of all, we propose three classifications in storage, i.e., Solid State Drive (SSD), Serial Attached SCSI (SAS) HDD, and Serial ATA (SATA) HDD, which are used for frequent accessed, inactive, and long-term preserved data blocks. To save the total time for data scans and data transfers, we secondly formulate two models in which the times when data transfers should be made: 1) Number N of data transfers from SSD to SAS; 2) Time T of data transfers from SAS to SATA. We suppose that data scans occur at non-homogeneous and homogeneous Poisson processes, and optimize respective models in number N and time T. Finally, two cases of numerical examples are given to illustrate the proposed models.