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AssigneeLSI Logic Corporation
InventorsDonald R. Humlicek, Charles E. Nichols, William P. Delaney
Estimating the term…
Disclosed is a method for continuing a rebuilding process of a RAID system by flagging a block of data as being bad when a media error or other error occurs that prohibits the reconstruction of data. The block of data may be flagged by writing a bad error correction code to the block of data, by keeping a log of bad blocks of data, or by otherwise indicating that the block of data is known bad.
A method of handling an error during the rebuilding of a replaced disk in a RAID system comprising:
A RAID system capable of handling an error during a rebuild process comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Parity data used in redundant arrays of independent storages, e.g. in RAID systems: rebuilding, e.g. when physically replacing a failing disk
Indexing scheme relating to G06F11/1076: metadata, i.e. metadata associated with RAID systems with parity
Computing and data processing
Term ended 3 Oct 2023 (estimated)
a. Field of the Invention
The present invention pertains generally to redundant arrays of independent disks (RAID) and specifically to reconstruction of data on RAID devices.
b. Description of the Background
In the drawings,
FIG. 1 is an illustration of the concept of creating parity in the RAID 5 standard.
FIG. 2 is an illustration of the placement of data and parity across the various disk drives in the RAID 5 standard with five drives in the array.
FIG. 4 illustrates an embodiment 400 of the present invention wherein a media error is encountered in a rebuilding process. When a drive has failed and is replaced, if a media error or other local problem precludes the reconstruction of a stripe of data, the block on the reconstructed drive is marked as bad and rebuilding can continue. Because of the media error, the XOR function cannot be completed and thus a data loss will have occurred.
Blocks 402, 404, 406, 408, and 410 represent a stripe of a five-disk RAID 5 system in degraded mode. Block 402 represents the data from disk 0. Block 404 represents the data from disk 1 wherein a media error prohibits access to the data. Block 406 represents the parity data. Block 408 represents the data from disk 3, and block 410 represents data on the failed disk 4.
Blocks 412, 414, 416, 418, and 420 represent the same stripe as above during the rebuilding process. Because block 414 of disk 1 has a media error, the data for the rebuilding of drive 4 cannot be constructed. In the prior art of rebuilding a RAID device, the controller may halt the rebuild process due to the media error in block 414. If the controller were to continue, any data placed onto the block 420 would be corrupt because the data of block 414 were known bad.