Accessing a hard disk drive and a flash memory with different formats in a storage system

摘要

For a storage apparatus where flash memory disks and hard disks coexist, high-density mounting of flash memory modules is achieved. The storage apparatus includes flash memories and a storage controller. A second storage apparatus including magnetic disks is connected to the storage apparatus. The storage controller can form a storage area using a flash memory or a magnetic disk to create a logical volume. When an input/output request is issued from a host computer, if a storage area is formed with a flash memory, the storage controller directly accesses the flash memory to handle the request. When the storage apparatus defines a storage area formed with a flash memory, the storage apparatus defines the storage area by adding up the capacity of a storage area to be provided for the host computer and a substitute area capacity determined in consideration of restrictions on the number deletions of the flash memory.

主权项

1. A storage system comprising:
a first storage apparatus comprising a flash memory module as an internal device of the first storage apparatus, the flash memory module including a plurality of memory chips to store data; a second storage apparatus comprising a hard disk drive (HDD) as an internal device of the second storage apparatus, the HDD storing data, wherein the second storage apparatus is connected to the first storage apparatus as an external storage apparatus external to the first storage apparatus; and a storage controller controlling access to the flash memory module and to the HDD, and comprising a usage table, the usage table storing a substitute area capacity per unit time required for each of a plurality of usages, wherein, for a given logical device, a substitute area capacity is allocated as a storage capacity of a storage area to be preserved as a substitute memory block, and the substitute area capacity is calculated as a product of a value of a useful life span of the given logical device and the substitute area capacity per unit time required based on the usage of the given logical device, wherein the storage controller is configured to receive access requests from a host with a Small Computer System Interface (SCSI) format, wherein, when the storage controller receives a first access request of the access requests, the first access request targeting first data on the HDD, the storage controller is configured to access the HDD with a SCSI format, and wherein, when the storage controller receives a second access request of the access requests, the second access request targeting second data on the flash memory module, the storage controller is configured to access the flash memory module with a direct access format, convert a logical unit number of a logical device allocated to the host to an address of the flash memory module if the flash memory module is an internal device, identify the flash memory module, and directly access the identified flash memory module to obtain the second data.