Method and system for file relocation

Patent metadata

Field	Value
Publication number	US-9256272-B2
Application number	US-46586309-A
Country	US
Kind code	B2
Filing date	May 14, 2009
Priority date	May 16, 2008
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A method and system for file relocation is provided. A file relocation system is connected to multiple storage devices. The system obtains a number of times that each of a number of files stored on the multiple storage devices is requested simultaneously with a concerned file. The relocation system then classifies multiple files into multiple groups, such that groups of files simultaneously are put together into one group. Multiple files classified in to the same group are then relocated to a single storage device. The relocation system then switches a storage device not accessed for a certain period of time into a power-saving mode.

First claim

What is claimed is:

1. A file relocation method comprising:
reading access request history information of each of a plurality of files, the access request history information including a list of access requests containing identification information of each file accessed, the access requests listed in the order that they are received;
determining a quantity of access requests for each of the plurality of files that have occurred simultaneously with a request for access for a concerned file;
determining the quantity of simultaneous access requests that each of the plurality of files has been requested to be accessed with the concerned file, wherein access requests within a defined time period surrounding an access request of the concerned filed are regarded as being accessed simultaneously with the concerned file;
performing a classifying operation on the plurality of files for classifying some of the plurality of files into a plurality of groups, a first of the groups comprising files that are simultaneously repeatedly access requested with the concerned file, the other groups each comprising files that are simultaneously repeatedly access requested with other concerned files;
after the classifying operation, classifying any unclassified files that were analyzed in the classifying operation into a new single group of files;
relocating files classified in the first group of files into a first storage device, the files in the first group being stored together on the first storage device as a result of the relocating;
relocating files classified in the new group of files into the first storage device or a second storage device, the files in the new group being stored together on the first storage device, or on the second storage device, as a result of the relocating;
invoking a power-saving mode in a storage device not accessed for a predetermined time; and further comprising:
(a) calculating a co-occurrence vector for each file to be relocated, the co-occurrence vector containing an access request frequency component, the access request frequency component comprising the frequency that each file to be relocated was access requested simultaneously with the concerned file;
(b) determining a reference co-occurrence vector, the reference co-occurrence vector containing an access request frequency component of a most requested file of the plurality of files to be relocated;
(c) calculating an inner product of the co-occurrence vector of each file of the plurality of files to be relocated;
(d) classifying files having an inner product equal to or greater than a predetermined value into a group, the group including the most requested file that contains the reference co-occurrence vector; and
(e) acquiring K, where K is the number of storage devices into which files are to be relocated; and
(f) repeating steps b through d for ungrouped files K−1 number of times, on condition that there is a file whose inner product with the reference co-occurrence vector is equal to or greater than the predetermined value in the step.

2. The method of claim 1 further comprising: excluding files having a low access request frequency component from the plurality of files stored in the storage devices.

3. The method of claim 2 further comprising: defining a plurality of time periods by equally dividing a unit observation time, the unit observation time for observing access requests of each file; and associating each file with one time period where the file was access requested the largest number of times.

4. The method of claim 1 further comprising associating each file with only one of a plurality of time periods in which the file was access requested the largest number of times, thereby defining a unique set of files associated with each of the time periods.

5. The method of claim 1 further comprising after the classifying the unclassified files into the new group of files, sending a notification that classification processing has been completed.

6. A file relocation method implemented in a controller that controls input and output of a plurality of storage devices, the method comprising:
reading history information on access requests for each file of a plurality of files from a memory of the controller, the access request history information including a list of access requests containing identification information of each file accessed, the access requests listed in the order that they are received;
obtaining an access request frequency for each file of the plurality of files;
determining the quantity of simultaneous access requests that each of the plurality of files has been requested to be accessed with a concerned file, wherein access requests within a defined time period surrounding an access request of the concerned filed are regarded as being accessed simultaneously with the concerned file;
defining a plurality of time periods;
associating each file of the plurality of files with only one of the plurality of defined time periods in which the respective file was access requested the largest number of times, thereby defining a unique set of files associated with each of the defined time periods;
classifying the set of files associated with each of the defined time periods into a plurality of groups of files, each group of files comprising a plurality of files with similar access request frequencies;
relocating each group of files, each group being relocated to one of the storage devices;
monitoring access requests of the plurality of storage devices;
invoking a power-saving mode on a storage device of the plurality of storage devices when the storage device is not accessed for a fixed time; and
(a) calculating a co-occurrence vector for each file to be relocated, the co-occurrence vector containing an access request frequency component, the access request frequency component comprising the frequency that each file to be relocated was access requested simultaneously with the concerned file;
(b) determining a reference co-occurrence vector, the reference co-occurrence vector containing an access request frequency component of a most requested file of the plurality of files to be relocated;
(c) calculating an inner product of the co-occurrence vector of each file of the plurality of files to be relocated;
(d) classifying files having an inner product equal to or greater than a predetermined value into a group, the group including the most requested file that contains the reference co-occurrence vector; and
(e) acquiring K, where K is the number of storage devices into which files are to be relocated; and
(f) repeating steps b through d for ungrouped files K−1 number of times, on condition that there is a file whose inner product with the reference co-occurrence vector is equal to or greater than the predetermined value.

7. The method of claim 6 further comprising:
excluding files having a low access request frequency component from the plurality of files stored in the plurality of storage devices.

8. The method of claim 7 further comprising: defining the plurality of time periods by equally dividing a unit observation time, the unit observation time for observing access requests of each file; and associating each file with the time period where the file was access requested the largest number of times.

9. The method of claim 6 wherein the history information includes the access requests arranged in chronological order as received by the controller.

10. The method of claim 6 further comprising after the classifying operation, classifying any unclassified files into a new single group of files;
and relocating files classified in the new group of files into a single one of the storage devices.

Assignees

• Hasegawa Tohru
• Kamiya Masanori
• IBM

Inventors

• Hasegawa Tohru
• Kamiya Masanori

Classifications

• G06F1/3221 Primary

  of disk drive devices · CPC title

• G06F17/30067

  Physics · mapped topic

• G11B27/105

  of operating discs · CPC title

• Y02B60/1246

  Cross-Sectional Technologies · mapped topic

• H04N21/84

  Generation or processing of descriptive data, e.g. content descriptors {(systems specially adapted for using meta-information in broadcast systems H04H60/73)} · CPC title