US 7,257,675 B2Granted

Disk array device having snapshot simulation function

AssigneeNEC Corporation

InventorTomohiro Sakai

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Abstract

A disk array device enabling an appropriate estimation of a physical disk capacity necessary prior to introducing a snapshot function. If a valid flag of the snapshot simulation function of a specified logical volume is on at receiving a data updating request from the host 100, snapshot simulation function control means 21 inquiries with update range determination means 10 and receives notice of bits on a bitmap corresponding to a range of update data, sets corresponding bits on a bitmap of the specified logical volume of bitmap information storage means 12 by means of bitmap information updating means 11, and executes data updating processing. Upon receiving an instruction of reporting a simulation result, snapshot simulation result reporting means 22 reports a physical disk capacity of the snapshot calculated by the snapshot simulation function.

Claims9

Dependent claims

A disk array device having a snapshot simulation function, comprising:

bitmap information storage means for storing a bitmap indicating presence or absence of updating for each management unit of a logical volume;
bitmap information updating means for updating the bitmap of said bitmap information storage means;
updating range determination means for determining which management units of the logical volume cover a range of specified update data and giving notice of bits on the bitmap of said bitmap information storage means corresponding to the management units;
snapshot simulation function management means for turning on a valid flag of the snapshot simulation function according to an external instruction of starting the snapshot simulation function to start the snapshot simulation function and turning off the valid flag of the snapshot simulation function according to an external instruction of terminating the snapshot simulation function;
snapshot simulation function control means for inquiring with said updating range determination means and receiving notice of the bits on the bitmap corresponding to the range of update data, setting the corresponding bits on the bitmap in said bitmap information storage means by said bitmap information updating means, and executing data updating processing, if the valid flag of the snapshot simulation function is on when a data updating request is issued;
and
snapshot simulation result reporting means for checking the number of bits set on the bitmap of said bitmap information storage means, calculating and storing the number of bits multiplied by a management unit size as a physical disk capacity of a snapshot, resetting all bits on the bitmap of said bitmap information storage means by said bitmap information updating means, and reporting the physical disk capacity of the stored snapshot according to an external instruction of reporting the simulation result, when receiving an instruction of terminating the snapshot simulation function from said snapshot simulation function management means.

4 more elements

A disk array device having a snapshot simulation function, comprising:

bitmap information storage means for storing a valid flag indicating whether a snapshot simulation function is effective for each logical volume and a bitmap indicating presence or absence of updating for each management unit of the logical volume;
bitmap information updating means for updating the valid flag of said bitmap information storage means and the bitmap;
updating range determination means for determining which management units of the logical volume cover a range of specified update data and giving notice of bits on the bitmap corresponding to the logical volume of said bitmap information storage means corresponding to the management units;
snapshot simulation function management means for turning on a valid flag of the snapshot simulation function about a specified logical volume according to an external instruction of starting the snapshot simulation function to start the snapshot simulation function about the logical volume and turning off the valid flag of the snapshot simulation function of the specified logical volume according to an external instruction of terminating the snapshot simulation function to terminate the snapshot simulation function about the logical volume;
snapshot simulation function control means for inquiring with said updating range determination means and receiving notice of the bits on the bitmap corresponding to the range of update data, setting the corresponding bits on the bitmap for the specified logical volume in said bitmap information storage means by said bitmap information updating means, and executing data updating processing, if the valid flag of the snapshot simulation function about the specified logical volume is on when a data updating request is issued;
and
snapshot simulation result reporting means for checking the number of bits set on the bitmap corresponding to the logical volume of said bitmap information storage means, calculating and storing the number of bits multiplied by a management unit size as a physical disk capacity of a snapshot, resetting all bits on the bitmap corresponding to the logical volume in said bitmap information storage means by said bitmap information updating means, and reporting the physical disk capacity of the stored snapshot according to an external instruction of reporting the simulation result, when receiving an instruction of terminating the snapshot simulation function from said snapshot simulation function management means.

4 more elements

A program product embodied on a storage portion of a computer and comprising code that, when said program product is executed, subject said computer to operate as a disk array device comprising:

bitmap information storage means for storing a bitmap indicating presence or absence of updating for each management unit of a logical volume;
bitmap information updating means for updating the bitmap of said bitmap information storage means;
updating range determination means for determining which management units of the logical volume cover a range of specified update data and giving notice of bits on the bitmap of said bitmap information storage means corresponding to the management units;
snapshot simulation function management means for turning on a valid flag of the snapshot simulation function according to an external instruction of starting the snapshot simulation function to start the snapshot simulation function and turning off the valid flag of the snapshot simulation function according to an external instruction of terminating the snapshot simulation function;
snapshot simulation function control means for inquiring with said updating range determination means and receiving notice of the bits on the bitmap corresponding to the range of update data, setting the corresponding bits on the bitmap in said bitmap information storage means by said bitmap information updating means, and executing data updating processing, if the valid flag of the snapshot simulation function is on when a data updating request is issued;
and
snapshot simulation result reporting means for checking the number of bits set on the bitmap of said bitmap information storage means, calculating and storing the number of bits multiplied by a management unit size as a physical disk capacity of a snapshot, resetting all bits on the bitmap of said bitmap information storage means by said bitmap information updating means, and reporting the physical disk capacity of the stored snapshot according to an external instruction of reporting the simulation result, when receiving an instruction of terminating the snapshot simulation function from said snapshot simulation function management means.

4 more elements

A program product embodied on a storage portion of a computer and comprising code that, when said program product is executed, subject said computer to operate as a disk array device comprising:

bitmap information storage means for storing a valid flag indicating whether a snapshot simulation function is effective for each logical volume and a bitmap indicating presence or absence of updating for each management unit of the logical volume;
bitmap information updating means for updating the valid flag of said bitmap information storage means and the bitmap;
updating range determination means for determining which management units of the logical volume cover a range of specified update data and giving notice of bits on the bitmap corresponding to the logical volume of said bitmap information storage means corresponding to the management units;
snapshot simulation function management means for turning on a valid flag of the snapshot simulation function about a specified logical volume according to an external instruction of starting the snapshot simulation function to start the snapshot simulation function about the logical volume and turning off the valid flag of the snapshot simulation function of the specified logical volume according to an external instruction of terminating the snapshot simulation function to terminate the snapshot simulation function about the logical volume;
snapshot simulation function control means for inquiring with said updating range determination means and receiving notice of the bits on the bitmap corresponding to the range of update data, setting the corresponding bits on the bitmap for the specified logical volume in said bitmap information storage means by said bitmap information updating means, and executing data updating processing, if the valid flag of the snapshot simulation function about the specified logical volume is on when a data updating request is issued;
and
snapshot simulation result reporting means for checking the number of bits set on the bitmap corresponding to the logical volume of said bitmap information storage means, calculating and storing the number of bits multiplied by a management unit size as a physical disk capacity of a snapshot, resetting all bits on the bitmap corresponding to the logical volume in said bitmap information storage means by said bitmap information updating means, and reporting the physical disk capacity of the stored snapshot according to an external instruction of reporting the simulation result, when receiving an instruction of terminating the snapshot simulation function from said snapshot simulation function management means.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/968,017Filed 20 Oct 2004
Priority: JP 2003-36006721 Oct 2003
Published: US 2005/0086432 A121 Apr 2005
Granted: 14 Aug 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G06F 3/065
Horizontal data movement in storage systems, i.e. moving data in between storage devices or systems: replication mechanisms
G06F 3/0605
Improving or facilitating administration, e.g. storage management: by facilitating the interaction with a user or administrator
G06F 3/0632
Configuration or reconfiguration of storage systems: by initialisation or re-initialisation of storage systems
G06F 3/0689
Plurality of storage devices: disk arrays, e.g. RAID, JBOD