System and method for managing disk space in a thin-provisioned storage subsystem

a technology of storage subsystem and management system, which is applied in the direction of instruments, input/output to record carriers, computing, etc., can solve the problems of risk of being out of free space, segment of disk or storage area may not be installed,
US20060242378A1Inactive Publication Date: 2006-10-26HITACHI LTD
5 Cites 63 Cited by

Patent Information

Authority / Receiving Office
US · United States
Current Assignee / Owner
HITACHI LTD
Publication Date
2006-10-26
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

A system and method for managing disk space in a thin-provisioned storage subsystem. If a number of free segments in a free segment pool at a storage subsystem is detected as below a desired minimum, one or more of the following is performed: selecting and adding logical devices (LDEVs) from an internal storage as free segments to the free segment pool, transitioning LDEVs to a virtual device (VDEV), and / or selecting and adding LDEVs from an external storage as free segments to the free segment pool. The transitioning includes identifying partially used or completely used LDEVs and transitioning these to the VDEV. Data migration may also occur by: selecting a source segment at a VDEV for migration, reading data from the source segment, writing the data to a target segment, the target segment being a free segment from the free segment pool, and assigning the target segment to the VDEV.
Need to check novelty before this filing date? Find Prior Art

Description

BACKGROUND

[0001] 1. Field of the Invention

[0002] This invention relates to a storage area networking system, and more specifically to managing disk space in a thin-provisioned storage subsystem.

[0003] 2. Description of the Related Art

[0004] Management for an allocation-on-use system, also known as thin-provisioning, provides efficient storage space management for a virtual volume by allocating a certain sized storage area for data to be written. An allocation-on-use system should have a pool for free segments to allocate segments which store data during a host's write operation.

[0005] FIG. 1 shows a diagram of a contemporary thin-provisioning write operation. Initially, before use of a storage subsystem's allocation-on-use technology, an administrator typically assigns logical devices (LDEVs), which consist of disks based on a parity group with storage allocation for their Local Block Address, for a free segment pool 127. The storage subsystem divides the LDEVs into segments for...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More