System and method for distributing random and sequential data in a tiered storage system

1. A system controller for an information handling system, the information handling system including a plurality of physical storage resources arranged in a first tier and a second tier such that both a performance and a cost relative to capacity of the plurality of physical storage resources in the first tier are greater than those in the second tier, the system controller comprising:

a tier manager in electronic communication with the plurality of physical storage resources;

a combined logical address space of the plurality of physical storage resources divided into pages;

each page occupying a predetermined and an equivalent portion of combined logical address space;

the tier manager configured to perform operations including:

determining a seek distance value for each page, the seek distance value defined as an average seek distance between consecutive input-output accesses within a page;

determining an operation rate for each page, the operation rate defined as an average number of input-output operations per second to a given page;

determining an operation size value for each page, the operation size value defined as an average size of the input-output operations to a given page;

determining an elapsed time value for each page, the elapsed time value defined as a time that has elapsed since the last access to a given page;

calculating a relative randomness value for each page using at least the seek distance value, the operation rate, the operation size value, and the elapsed time value determined for each page;

comparing the relative randomness values for each page; and

a classification module in electronic communication with the tier manager and the plurality of physical storage resources, the classification module configured to perform operations including:

assigning a physical location for each page such that the relative randomness value for each page in the first tier is greater than the relative randomness value for each page in the second tier; and

relocating the pages according to the assigned physical location for each page.

2. A system controller according to claim 1 , wherein the tier manager determines and records the seek distance value, the operation rate, the operation size value, and the elapsed time value for each page.

3. A system controller according to claim 1 , further comprising the plurality of physical storage resources arranged in a third tier such that both a performance and a cost relative to capacity of the plurality of physical storage resources in the second tier are greater than those in the third tier.

4. A system controller according to claim 1 , wherein each time a physical storage resource is added to or removed from the information handling system the system controller:

identifies each of the plurality of physical storage resources associated with the information handling system, a combined logical address space of the plurality of physical storage resources divided into pages, each page occupying a predetermined and equivalent amount of logical address space; and

identifies each of the pages associated with the plurality of physical storage resources.

5. A system controller according to claim 1 , wherein calculating the relative randomness value for each page includes applying scaling factors to at least each of the seek distance value, the operation rate, the operation size value, and the elapsed time value determined for each page.

6. A system controller according to claim 1 , wherein calculating the relative randomness value for each page includes:

applying scaling factors to the seek distance value(SDV), the operation rate(OR), the operation size value (OSV), and the elapsed time value (ETV) determined for each page; and

calculating the relative randomness value, the relative randomness value defined as:

r ( x )=α*SDV+β*OR−γ*OSV−δ*ETV

7. A system controller according to claim 1 , wherein calculating the relative randomness value for each page includes:

applying scaling factors to the seek distance value(SDV), the operation rate(OR), the operation size value (OSV), and the elapsed time value (ETV) determined for each page; and

calculating the relative randomness value, the relative randomness value defined as:

r ( x )=α*SDV+β*OR−γ* g (OSV)−δ* h (ETV)

g(OSV) and h(ETV) defined as:

g(OSV)={1 if OSV≧n, 0 if OSV<n}

h(ETV)={1 if ETV≧t, 0 if ETV<t}

wherein n and t are determined by the overall system characteristics.

8. An information handling system comprising:

a plurality of physical storage resources;

wherein the plurality of physical storage resources comprises:

a first tier including one or more physical storage resources; and

a second tier including one or more physical storage resources, each of which has a lower performance and cost relative to capacity than each of the one or more physical storage resources of the first tier;

a combined logical address space of the plurality of physical storage resources divided into pages;

each page occupying a predetermined and an equivalent amount of logical address space;

a tier manager hosted on the information handling system and in electronic communication with the plurality physical storage resources, the tier manager configured to perform operations including:

determining a seek distance value for each page, the seek distance value defined as an average seek distance between consecutive input-output accesses within a page;

determining an operation rate for each page, the operation rate defined as an average number of input-output operations per second to a given page;

determining an operation size value for each page, the operation size value defined as an average size of the input-output operations to a given page;

determining an elapsed time value for each page, the elapsed time value defined as a time that has elapsed since the last access to a given page;

calculating a relative randomness value for each page using at least the seek distance value, operation rate, operation size value, and elapsed time value determined for each page;

comparing the relative randomness values for each page; and

a classification module in electronic communication with the tier manager and the plurality of physical storage resources, the classification module configured to perform operations including:

assigning a physical location for each page such that the relative randomness value for each page in the first tier is greater than the relative randomness value for each page in the second tier; and

relocating the pages according to the assigned physical location for each page.

9. An information handling system according to claim 8 , wherein the tier manager determines and records the seek distance value, the operation rate, the operation size value, and the elapsed time value determined for each page.

10. An information handling system according to claim 8 , further comprising the tier manager hosted on a system controller associated with the information handling system.

11. An information handling system according to claim 8 , further comprising the tier manager hosted on a general purpose computer associated with the information handling system.

12. An information handling system according to claim 8 , further comprising the tier manager hosted on an intelligent switch associated with the information handling system.

13. An information handling system according to claim 8 , further comprising the tier manager hosted on a distributed file system associated with the information handling system.

14. An information handling system according to claim 8 , further comprising:

a third tier including one or more physical storage resources, each of which has a lower performance and cost relative to capacity than each of the one or more physical storage resources of the second tier; and

wherein the classification module is configured to assigning a physical location for each page such that the relative randomness value for each page in the second tier is greater than the relative randomness value for each page in the third tier.

15. A method for distributing random and sequential data in an information handling system, the information handling system including a plurality of physical storage resources arranged in a first and second tier such that the performance and cost relative to capacity of the plurality of physical storage resources in the first tier is greater than those in the second tier, the method comprising:

determining a seek distance value for each page, the seek distance value defined as an average seek distance between consecutive input-output accesses within a page;

determining an operation rate for each page, the operation rate defined as an average number of input-output operations per second to a given page;

determining an operation size value for each page, the operation size value defined as an average size of the input-output operations to a given page;

determining an elapsed time value for each page, the elapsed time value defined as a time since the last access to the page;

calculating a relative randomness value for each page using at least the seek distance value, the operation rate, the operation size value, and the elapsed time value determined for each page;

comparing the relative randomness values for each page;

assigning a physical location for each page such that the relative randomness value for each page in the first tier is greater than the relative randomness value for each page in the second tier; and

relocating the pages according to the assigned physical locations for each page.

16. A method according to claim 15 , wherein the following operations are performed each time a physical storage resource is added to or removed from the information handling system, the method further comprising:

identifying each of the plurality of physical storage resources associated with the information handling system, a combined logical address space of the plurality of physical storage resources divided into pages, each page occupying a predetermined and equivalent amount of logical address space; and

identifying each of the pages associated with the plurality of physical storage resources.

17. A method according to claim 15 , wherein calculating the relative randomness value for each page includes:

applying scaling factors to at least each of the seek distance value, the operation rate, the operation size value, and the elapsed time value determined for each page.

18. A method according to claim 15 , wherein calculating the relative randomness value for each page includes:

applying scaling factors to the seek distance value(SDV), the operation rate(OR), the operation size value (OSV), and the elapsed time value (ETV) determined for each page; and

calculating the relative randomness value, the relative randomness value defined as:

r ( x )=α*SDV+β*OR−γ*OSV−δ*ETV

19. A method according to claim 15 , wherein calculating the relative randomness value for each page includes:

applying scaling factors to the seek distance value(SDV), the operation rate(OR), the operation size value (OSV), and the elapsed time value (ETV) determined for each page; and

calculating the relative randomness value, the relative randomness value defined as:

r ( x )=α*SDV+β*OR−γ* g (OSV)−δ* h (ETV)

g(OSV) and h(ETV) defined as:

g(OSV)={1 if OSV≧n, 0 if OSV<n}

h(ETV)={1 if ETV≧t, 0 if ETV<t}

wherein n and t are determined by the overall system characteristics.

20. A method according to claim 15 , wherein the plurality of physical storage resources includes a third tier such that the performance and cost relative to capacity of the plurality of physical storage resources in the second tier is greater than those in the third tier and further comprising assigning a physical location for each page such that the relative randomness value for each page in the second tier is greater than the relative randomness value for each page in the third tier.