Storage drive with defect management on basis of segments corresponding to logical erase units

A storage device comprising:

• flash memory, the flash memory to have one or more block devices at a hierarchically-superior level, segments within each of the block devices at a hierarchically-intermediate level, and addressable storage locations within each of the segments at a hierarchically-inferior level, each segment maps to a physical erase unit, each segment being associated with only one of the block devices, each physical erase unit being associated with no more than one of the segments;
• and
• circuitry to receive incoming data access requests and, for a first one of the incoming data access requests, accompanying address information, wherein said circuitry is to:
• derive, from the accompanying address information, a first address portion, a second address portion and a third address portion,
• identify an addressed one of the block devices from the first address portion,
• identify an addressed one of the segments within the addressed one of the block devices from the second address portion, wherein the addressed one of the segments is sized to have a storage capacity no greater than that corresponding to one of the physical erase units, and
• identify an addressed one of the addressable storage locations within the addressed one of the segments from the third address portion, and is to use a division operation on the third address portion to identify a physical page associated with the addressed one of the addressable storage locations within a first one of the physical erase units,
• wherein the circuitry is to service the first one of the incoming data access requests by accessing the identified physical page associated with the addressed one of the addressable storage locations;
• wherein the storage device is to detect a failure condition of the first one of the physical erase units, is to remap the addressed one of the segments to instead correspond to a second one of the physical erase units, for which the failure condition has not been detected, and is to service one or more subsequent ones of the incoming data access requests which are directed to the addressed one of the segments using the second one of the physical erase units.

A storage device comprising:

• flash memory, the flash memory to have one or more block devices at a hierarchically-superior level, segments within each of the block devices at a hierarchically-intermediate level, and addressable storage locations within each of the segments at a hierarchically-inferior level, each segment maps to a physical erase unit, each segment being associated with only one of the block devices, each physical erase unit being associated with no more than one of the segments;
• and
• circuitry to receive incoming data access requests and, for a first one of the incoming data access requests, accompanying address information, wherein said circuitry is to:
• derive, from the accompanying address information, a first address portion, a second address portion and a third address portion,
• identify an addressed one of the block devices from the first address portion,
• identify an addressed one of the segments within the addressed one of the block devices from the second address portion, wherein the addressed one of the segments is sized to have a storage capacity no greater than that corresponding to one of the physical erase units, and
• identify an addressed one of the addressable storage locations within the addressed one of the segments from the third address portion, and is to use a division operation on the third address portion to identify a physical page associated with the addressed one of the addressable storage locations within a first one of the physical erase units,
• wherein the circuitry is to service the first one of the incoming data access requests by accessing the identified physical page associated with the addressed one of the addressable storage locations;
• wherein the storage device is to detect a failure condition of the first one of the physical erase units, is to remap the addressed one of the segments to instead correspond to a second one of the physical erase units, for which the failure condition has not been detected, and is to service one or more subsequent ones of the incoming data access requests which are directed to the addressed one of the segments using the second one of the physical erase units;
• and
• wherein said circuitry is further to, subsequent to remapping of the addressable one of the segments to instead correspond to the second one of the physical erase units:
• maintain metadata for the second one of the physical erase units, the metadata representing a time since data was programmed in the second one of the physical erase units;
• responsive to a determination that the metadata meets at least one criterion, copy data from the second one of the physical erase units to a third one of the physical erase units;
• and
• remap the addressable one of the segments to the third one of the physical erase units instead of the second one of the physical erase units.

A method of operation in a storage device having flash memory, the flash memory having physical erase units, the method comprising, with circuitry of the storage device:

• receiving incoming data access requests, wherein a first one of the incoming data access requests is accompanied by address information;
• processing the address information to, for the first one of the incoming data access requests:
• derive, from the accompanying address information, a first address portion, a second address portion and a third address portion,
• identify an addressed block device from the first address portion,
• identify an addressed segment within the addressed block device from the second address portion, wherein the addressed segment is sized to have a storage capacity no greater than that corresponding to one of the physical erase units,
• identify an addressed storage location within the addressed segment from the third address portion, and is to use a division operation on the third address portion to identify a physical page associated with the addressed storage location within a first one of the physical erase units, and
• service the first one of the incoming data access requests by accessing the identified physical page associated with the addressed storage location;
• detecting a failure condition of the first one of the physical erase units;
• responsively remapping the addressed segment to instead correspond to a second one of the physical erase units, for which the failure condition has not been detected;
• and
• servicing one or more subsequent ones of the incoming data access requests which are directed to the addressed segment using the second one of the physical erase units.