US 7,386,758 B2 · Method and apparatus for reconstructing data in object-based storage arrays · patentgrep

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Abstract

A method and apparatus for placing objects on a storage device of a storage system and reconstructing data of objects in the storage device. The storage system stores data as objects and implements a RAID architecture including a plurality of the storage devices, and a disk controller for processing Object-based Storage Device (OSD) commands. Each object includes data and attribute. Parity data is calculated for reconstructing an object upon occurrence of a storage device failure. Each storage device includes plural stripes each having a predetermined length. Each object is stored in a stripe wherein an attribute is stored in the head of the stripe and data is stored after the attribute. When the object size exceeds the stripe length, the remainder of the object is stored in the next stripe, and when another object is to be stored, an attribute is stored at a head of a further next stripe and data is stored just after the attribute.

Claims14

Dependent claims

A storage system for storing data as objects comprising:

a plurality of storage devices;
and
a disk controller for controlling said storage devices,
wherein each of said objects includes attribute which defines attributes of the object and data,
wherein said storage devices are configured to implement a Redundant Array of Inexpensive Disks (RAID) architecture,
wherein each of said storage devices is formatted to include a plurality of stripes each having a predetermined length and at least one logical unit (LU) is formed by all or a portion of one or a plurality of said storage devices,
wherein each object is stored on said LU such that an attribute of the object is stored in the head of a stripe and data of the object is stored just after the attribute,
wherein when another object is to be stored, an attribute of the another object is stored at a head of the next stripe and data of the another object is stored just after the attribute in the next stripe, said stripe which includes attribute and data or data is referred to as a data stripe,
wherein according to the RAID architecture being implemented, parity data is calculated based on certain ones of the data stripes, said parity data is stored in a stripe of a storage device and such stripe is referred as a parity stripe, and
wherein the RAID architecture being implemented is defined according to a RAID configuration table which includes a plurality of entries each including a port identifier ID, a logical unit number (LUN), a storage device (disk) ID, a RAID level, and a stripe size, thereby defining for each combination of port ID and LUN, a logical storage device which is formed by all or a portion of one or a plurality of said storage devices and a RAID level and stripe size to be used on said logical storage device.

7 more elements

A storage system for storing data as objects comprising:

a plurality of storage devices;
and
a disk controller for controlling said storage devices,
wherein each of said objects includes attribute which defines attributes of the object and data,
wherein said storage devices are configured to implement a Redundant Array of Inexpensive Disks (RAID) architecture,
wherein each of said storage devices is formatted to include a plurality of stripes each having a predetermined length and at least one logical unit (LU) is formed by all or a portion of one or a plurality of said storage devices,
wherein each object is stored on said LU such that an attribute of the object is stored in the head of a stripe and data of the object is stored just after the attribute,
wherein when another object is to be stored, an attribute of the another object is stored at a head of the next stripe and data of the another object is stored just after the attribute in the next stripe, said stripe which includes attribute and data or data is referred to as a data stripe,
wherein according to the RAID architecture being implemented, parity data is calculated based on certain ones of the data stripes, said parity data is stored in a stripe of a storage device and such stripe is referred as a parity stripe,
wherein a logical-physical (LP) mapping table is used by said storage system to manage relations between objects and stripes,
wherein said LP mapping table is used to search for a location of an object when said storage system receives an I/O command, and
wherein said LP mapping table includes a plurality of entries each having a port identifier (ID) which identifies a particular port through which a logical storage device can be accessed, a logical unit number (LUN) which identifies a particular logical unit (LU) where an object is stored, a partition ID which identifies a partition on a storage device which forms the LU within which the object is stored, an object ID which identifies the object, and disk location information which identifies in which stripe the object, specified by the partition ID and object ID, is stored.

9 more elements

A storage system for storing data as objects comprising:

a plurality of storage devices;
and
a disk controller for controlling said storage devices,
wherein each of said objects includes attribute which defines attributes of the object and data,
wherein said storage devices are configured to implement a Redundant Array of Inexpensive Disks (RAID) architecture,
wherein each of said storage devices is formatted to include a plurality of stripes each having a predetermined length and at least one logical unit (LU) is formed by all or a portion of one or a plurality of said storage devices,
wherein each object is stored on said LU such that an attribute of the object is stored in the head of a stripe and data of the object is stored just after the attribute,
wherein when another object is to be stored, an attribute of the another object is stored at a head of the next stripe and data of the another object is stored just after the attribute in the next stripe, said stripe which includes attribute and data or data is referred to as a data stripe,
wherein according to the RAID architecture being implemented, parity data is calculated based on certain ones of the data stripes, said parity data is stored in a stripe of a storage device and such stripe is referred as a parity stripe,
wherein a physical-logical (PL) mapping table is used by said storage system to manage relations between disk blocks of each of said storage systems and objects,
wherein said PL mapping table is used to search which disk block contains a particular object, and
wherein said PL mapping table includes a plurality of entries each having a stripe identifier (ID) which identifies a particular stripe which contains a particular object, a port ID which identifies a particular port through which a logical storage device can be accessed, a logical unit number (LUN) which identifies a particular logical unit (LU) where the object is stored, a partition ID which identifies a partition on a storage device which forms the LU within which the object is stored, and an object ID which identifies the object.

9 more elements

A storage system for storing data as objects comprising:

a plurality of storage devices;
and
a disk controller for controlling said storage devices,
wherein each of said objects includes attribute which defines attributes of the object and data,
wherein said storage devices are configured to implement a Redundant Array of Inexpensive Disks (RAID) architecture,
wherein each of said storage devices is formatted to include a plurality of stripes each having a predetermined length and at least one logical unit (LU) is formed by all or a portion of one or a plurality of said storage devices,
wherein each object is stored on said LU such that an attribute of the object is stored in the head of a stripe and data of the object is stored just after the attribute,
wherein when another object is to be stored, an attribute of the another object is stored at a head of the next stripe and data of the another object is stored just after the attribute in the next stripe, said stripe which includes attribute and data or data is referred to as a data stripe,
wherein according to the RAID architecture being implemented, parity data is calculated based on certain ones of the data stripes, said parity data is stored in a stripe of a storage device and such stripe is referred as a parity stripe,
wherein when one of said storage devices fails, a data reconstruction process is implemented such that data recovery is performed on each data stripe where an object or a part of said object is stored,
wherein when a storage device fails, said storage system creates for said storage device a list of stripes included in said storage device within which objects are stored, and
wherein said list is a disk reconstruction bitmap which includes a plurality of entries each including a stripe identifier (ID) which identifies a particular stripe, recovery information which indicates whether the identified stripe is to be recovered, and done information which indicates whether the data reconstruction of the identified stripe has been completed.

9 more elements

A storage system for storing data as objects comprising:

a plurality of storage devices;
and
a disk controller for controlling said storage devices,
wherein each of said objects includes attribute which defines attributes of the object and data,
wherein said storage devices are configured to implement a Redundant Array of Inexpensive Disks (RAID) architecture,
wherein each of said storage devices is formatted to include a plurality of stripes each having a predetermined length and at least one logical unit (LU) is formed by all or a portion of one or a plurality of said storage devices,
wherein each object is stored on said LU such that an attribute of the object is stored in the head of a stripe and data of the object is stored just after the attribute,
wherein when another object is to be stored, an attribute of the another object is stored at a head of the next stripe and data of the another object is stored just after the attribute in the next stripe, said stripe which includes attribute and data or data is referred to as a data stripe,
wherein according to the RAID architecture being implemented, parity data is calculated based on certain ones of the data stripes, said parity data is stored in a stripe of a storage device and such stripe is referred as a parity stripe,
wherein when a storage device fails, a data reconstruction process is implemented such that data recovery is performed on each data stripe where an object or a part of said object is stored, and
wherein during said data reconstruction process isolated stripes each being stored at locations on a storage device separated from other stripes are relocated to be adjacent to the other stripes.

8 more elements

Dependencies are inferred from the claim text.