Invention Grant
US07921081B2 Managing a snapshot stored within a file system space for efficient detection of in-use blocks
失效
管理存储在文件系统空间内的快照,以有效检测使用中的块
- Patent Title: Managing a snapshot stored within a file system space for efficient detection of in-use blocks
- Patent Title (中): 管理存储在文件系统空间内的快照,以有效检测使用中的块
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Application No.: US11755315Application Date: 2007-05-30
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Publication No.: US07921081B2Publication Date: 2011-04-05
- Inventor: Janet E. Adkins , Joon Chang
- Applicant: Janet E. Adkins , Joon Chang
- Applicant Address: US NY Armonk
- Assignee: International Business Machines Corporation
- Current Assignee: International Business Machines Corporation
- Current Assignee Address: US NY Armonk
- Agent Matthew W. Baca; Amy J. Pattillo
- Main IPC: G06F7/00
- IPC: G06F7/00 ; G06F17/00 ; G06F12/00 ; G06F13/00 ; G06F15/16

Abstract:
In one embodiment, at least one snapshot thread manages a point in time snapshot of a file system stored within the space allocated to the file system. The snapshot thread tracks, for at least one block of the plurality of blocks of the file system, a separate entry in a snapshot map specifying if each at least one block is newly allocated following the creation of the point in time snapshot and specifying an addressed location of a snapshot copy of the at least one block if copied. Separately, a file system handling thread tracks a mapping of an allocation state of each of said plurality of blocks of the file system. Responsive to detecting the file system triggered to write or delete a particular block from among the at least one block of the file system, the snapshot thread allows the file system to write to or delete the particular block without making a snapshot copy of the particular block if a particular entry for the particular block in the snapshot map specifies the particular block is newly allocated, wherein a block marked newly allocated was not in-use at the point in time of the file system snapshot.
Public/Granted literature
- US20080301203A1 MANAGING A SNAPSHOT STORED WITHIN A FILE SYSTEM SPACE FOR EFFICIENT DETECTING OF IN-USE BLOCKS Public/Granted day:2008-12-04
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