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Method for quickly initializing bitmap page management by RAID5

A RAID-5 and page management technology, applied in the direction of memory address/allocation/relocation, input/output to record carrier, etc., can solve problems such as wrong results, inconsistent stripes, loss of redundancy, etc.

Inactive Publication Date: 2012-07-11
LANGCHAO ELECTRONIC INFORMATION IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For reading and writing, the participation of the old verification data is required. Therefore, if the original stripe data is inconsistent, the reading and writing depends on the original verification value. After recalculation, the wrong result will be generated, and the stripes will still be inconsistent. , loses the role of redundancy

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  • Method for quickly initializing bitmap page management by RAID5
  • Method for quickly initializing bitmap page management by RAID5
  • Method for quickly initializing bitmap page management by RAID5

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Embodiment Construction

[0017] The method of the present invention is described in detail below with reference to the accompanying drawings.

[0018] The invention is developed on the basis of soft RAID in the linux kernel. Use a bitmap to mark areas that have been written or synchronized. When RAID-5 processes a stripe write request, it first judges whether the bit in the bitmap corresponding to the stripe is 0. If it is 0, it means that the stripe is out of sync, and the write request is processed by reconstructing the write method. After completion, position 1 in the corresponding bitmap indicates that the stripes have been synchronized. Further, when all the stripes have been synchronized, the RAID-5 is marked as "synchronized".

[0019] The case where a bit in a bitmap corresponds to a stripe has been done before. However, one bit corresponding to one strip has many limitations in actual use. If each stripe is 4KB corresponding to 1 bit to divide, for a 2TB disk, the bitmap needs about 62MB. ...

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Abstract

The invention provides a method for quickly initializing bitmap page management by a redundant array of inexpensive disks 5 (RAID5). The method comprises the following steps of: marking the written or synchronized region with a bitmap; when the RAID-5 processes a stripe writing request, firstly judging whether the bit in the bitmap corresponding to the stripe is 0, if so, indicating that the stripe is asynchronous; processing the writing request by a reconstruct write mode; setting the bit in the corresponding bitmap to be 1 after stripe writing so as to indicate that the stripe is synchronized; and when all the stripes are synchronized, marking the RAID-5 with the 'synchronized' state.

Description

technical field [0001] The invention relates to the field of computer systems and storage, in particular to a method for quickly initializing bitmap page management in RAID5. Background technique [0002] For a RAID5 system with redundant verification information, the data of each member disk cannot guarantee the consistency of the stripe data when the RAID5 is newly created. The inconsistency of the data makes the system unable to process the host IO request according to the normal process, and the obtained verification Data may be wrong, so these levels of RAID5 must first be created with consistent initialization. A typical initialization method is to format all member disks, and write zero to all member disk data to ensure that the RAID5 stripe data conforms to even parity. [0003] However, the RAID5 initialization task must traverse all the data on the member disks, which is a very time-consuming task, and as the disk capacity increases, the waiting time will be longe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F12/02G06F3/06
Inventor 古世磊施培任
Owner LANGCHAO ELECTRONIC INFORMATION IND CO LTD