Storage system

摘要

Regarding a method for migrating a file system by copying a file from a migration source to a migration destination and deleting the file at the migration source, a retention of a file in a page (allocation unit of a thin provisioning function) is either suppressed or solved, and two methods are proposed for solving the problems and for enabling migration of a file system in which the increase of utilization of storage capacity is suppressed, wherein one method changes the location of a file prior to performing copying so that the file to be copied next is located in the same page, and another method creates a reverse index table to recognize which block is used by files, thereby enabling to specify the file remaining within a page and copy the same by referring to this reverse index table.

主权项

1. A storage system comprising:
a file server having a first processor and first memory having instructions that, when executed by the first processor, cause the first processor to manage a plurality of files; and a storage subsystem having a plurality of storage devices, a second processor and second memory having instructions that, when executed by the second processor, cause the second processor to: provide a pool area managed as a plurality of pages, and store file data of the files managed by the file server by allocating the pool area in units via the plurality of pages,
wherein, when the file server receives a copy command regarding a plurality of target files of the files stored in the pool area, the first processor is further caused to:sequentially copy the target files to a newly allocated pool area, release the pages in which the file data of each of the target files having been copied has been stored, andwhen a utilization rate of the pool area exceeds a predetermined threshold:
specify one of said target files stored in N number of pages, N being an integer of 2 or greater,specify a next target file to be sequentially copied immediately after the specified target file stored in the N number of pages,change the location of the file data of the specified next target file so that the specified target file and specified next target file are located in N−1 or fewer pages, and to free one or more pages from storing the file data thereof,immediately release the one or more pages having been freed by the location change,wherein the file data of the specified target file and the specified next target file are located in the N−1 or fewer pages in an order in which the file data thereof is to be sequentially copied.