# US 10,121,511 B2 · Forward corrupted track detection and by-pass for shingled magnetic recording drives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,511 B2 - Document ID: US10121511B2 - Status: Granted - Kind: B2 - Application number: 15/887,338 - Filed: 2018-02-02 - Published: 2018-06-28 - Granted: 2018-11-06 - Earliest claimed: 2016-06-01 - Assignees: Seagate Technology LLC - Applicants: Seagate Technology LLC - Inventors: Junghwan Shin; Jae Ik Song; Dong Hyuck Shin; Eun Yeong Hong - Web page: https://patentgrep.com/patent/US10121511B2 ## CPC - G11B 20/1816: {Testing} - G11B 2020/1823: {wherein a flag is set when errors are detected or qualified} - G11B 2020/1826: {wherein a defect list or error map is generated} - G11B 2020/183: {wherein at least one additional attempt is made to read or write the data when a first attempt is unsuccessful} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract Systems and methods for forward corrupted track detection and by-pass are described. In one embodiment, a storage system comprising a storage controller performs a read operation for a target track of a shingled magnetic recording (SMR) disk drive and detects a read operation failure of the read operation for the target track. The storage controller also performs a boundary track read operation on one or more tracks including or adjacent to the target track and detect a forward corruption area based on the boundary track read operation. In another embodiment, a method is provided that includes detecting a read operation failure of a read operation for a track of a disk drive and performing a boundary track read operation on one or more tracks including or adjacent to the target track. The method also includes detecting a forward corruption area based on the boundary track read operation. ## Claims ### Claim 1 A storage system comprising a storage controller to: detect a read operation failure of a read operation associated with a sector of a target track of a shingled magnetic recording (SMR) disk drive; determine whether the sector of the target track is within a track skew range; determine whether the sector of the target track is a first sector of the target track; and upon determining the sector of the target track is within the track skew range, sample at least one of a sector of a track adjacent to the target track at a same wedge of the sector of the target track, a sector of a track adjacent to the target track at a same wedge of the target track where a forward corruption area starts, or one or more sectors sampled when the sector of the target track is the first sector of the target track, or any combination thereof. ### Claim 2 (depends on 1) The storage system of claim 1, the storage controller further to: upon determining the sector of the target track is the first sector of the target track, sample at least one of a first sector of a track adjacent to the target track, a last sector of the target track, and the sector of the target track, or any combination thereof. ### Claim 3 (depends on 1) The storage system of claim 1, the storage controller further to: identify where the forward corruption area starts based at least in part on detecting the read operation failure. ### Claim 4 (depends on 1) The storage system of claim 1, the storage controller further to: identify one or more sectors of the forward corruption area based at least in part on whether the sector of the target track is the first sector of the target track. ### Claim 5 (depends on 1) The storage system of claim 1, wherein the first sector being within the track skew range indicates the first sector is affected by track skew. ### Claim 6 (depends on 5) The storage system of claim 5, wherein track skew includes a rotational offset between a last sector of a track previous to the target track and the first sector of the target track. ### Claim 7 (depends on 1) The storage system of claim 1, the storage controller further to: upon determining the sector of the target track is within the track skew range, sample at least one of a last sector of a track adjacent to the target track, and one or more sectors sampled when the target track is within the track skew range, or any combination thereof. ### Claim 8 (depends on 1) The storage system of claim 1, the storage controller further to: upon determining the sector of the target track is not within the track skew range, sample a last sector of a next track in a direction of a writing operation or the one or more sectors that are sampled when the target track is within the track skew range, or both. ### Claim 9 (depends on 1) The storage system of claim 1, the storage controller further to: identify the one or more sectors within the forward corruption area as bad sectors. ### Claim 10 (depends on 1) The storage system of claim 1, the storage controller, upon receiving a read command, further to: store at least one of: which sectors are sampled, an indication whether a sampled sector is a bad sector, and a location of each bad sector, or any combination thereof. ### Claim 11 (depends on 1) The storage system of claim 1, the storage controller further to: rewrite data previously written to the forward corruption area. ### Claim 12 An apparatus comprising: a storage drive configured for incorporation into a data center or data cloud environment; and a controller to: detect a read operation failure of a read operation associated with a sector of a target track of a shingled magnetic recording (SMR) disk drive; determine whether the sector of the target track is within a track skew range, the first sector being within the track skew range indicating the first sector is affected by track skew; determine whether the sector of the target track is a first sector of the target track; and upon determining the sector of the target track is within the track skew range, sample at least one of a sector of a track adjacent to the target track at a same wedge of the sector of the target track, a sector of a track adjacent to the target track at a same wedge of the target track where a forward corruption area starts, or one or more sectors sampled when the sector of the target track is the first sector of the target track, or any combination thereof. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein the controller is further configured to: upon determining the sector of the target track is the first sector of the target track, sample at least one of a first sector of a track adjacent to the target track, a last sector of the target track, and the sector of the target track, or any combination thereof. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein the controller is further configured to: identify where the forward corruption area starts based at least in part on detecting the read operation failure. ### Claim 15 (depends on 12) The apparatus of claim 12, wherein the controller is further configured to: identify one or more sectors of the forward corruption area based at least in part on whether the sector of the target track is the first sector of the target track. ### Claim 16 (depends on 12) The apparatus of claim 12, wherein track skew includes a rotational offset between a last sector of a track previous to the target track and the first sector of the target track. ### Claim 17 (depends on 12) The apparatus of claim 12, wherein the controller is further configured to: upon determining the sector of the target track is within the track skew range, sample at least one of a last sector of a track adjacent to the target track, and one or more sectors sampled when the target track is within the track skew range, or any combination thereof. ### Claim 18 (depends on 12) The apparatus of claim 12, wherein the controller is further configured to: upon determining the sector of the target track is not within the track skew range, sample a last sector of a next track in a direction of a writing operation or the one or more sectors that are sampled when the target track is within the track skew range, or both. ### Claim 19 A method comprising: detecting a read operation failure of a read operation associated with a sector of a target track of a shingled magnetic recording (SMR) disk drive; determining whether the sector of the target track is within a track skew range; determining whether the sector of the target track is a first sector of the target track; and upon determining the sector of the target track is within the track skew range, sampling at least one of a sector of a track adjacent to the target track at a same wedge of the sector of the target track, or a sector of a track adjacent to the target track at a same wedge of the target track where a forward corruption area starts, or any combination thereof. ### Claim 20 (depends on 19) The method of claim 19 further comprising: upon determining the sector of the target track is the first sector of the target track, sampling at least one of a first sector of a track adjacent to the target track, a last sector of the target track, and the sector of the target track, or any combination thereof.