Method of storage management, storage system and computer program product
Embodiments of the present disclosure provide a method of storage management, a storage system and a computer program product. The method comprises determining whether a number of I/O requests for a first page in a disk of a storage system exceeds a first threshold. The method further comprises: in response to determining that the number exceeds the first threshold, caching data in the first page to a first cache of the storage system; and storing metadata associated with the first page in a Non-Volatile Dual-In-Line Memory Module (NVDIMM) of the storage system.
1. A method of storage management, comprising:
determining whether a number of I/O requests for a first page in a disk of a storage system exceeds a first threshold;
in response to determining that the number exceeds the first threshold,
caching data in the first page to a first cache of the storage system;
storing metadata associated with the first page in a Non-Volatile Dual-In-Line Memory Module (NVDIMM) of the storage system; and
in response to receiving a write request for the cached first page,
caching the data in the first page to a second cache of the storage system;
releasing space occupied by the data in the first page on the first cache;
writing data related to the write request into the second cache; and
updating the metadata associated with the first page in the NVDIMM.
2. The method of claim 1 , wherein the first cache comprises a solid-state disk with first endurance and the second cache comprises at least two solid-state disks with second endurance organized into a Redundant Array of Independent Disks (RAID), the second endurance being higher than the first endurance.
3. The method of claim 2 , wherein the first cache is a read-preference cache, and the second cache is a write cache.
4. The method of claim 1 , wherein updating the metadata associated with the first page comprises:
changing status of the first page to be dirty; and
modifying mapping information associated with the first page to indicate that the first page is mapped to the second cache.
5. The method of claim 1 , further comprising:
in response to a number of cached pages on the second cache exceeding a second threshold, flushing the cached pages to the disk; and
changing status of the cached pages to be clean.
6. The method of claim 1 , further comprising:
in response to a number of cached pages on the second cache exceeding a third threshold, limiting a number of write requests to enter the second cache.
7. The method of claim 6 , wherein limiting the number of write requests to enter the second cache comprises one of:
sending to an upper layer driver an indication to limit the number of write requests to enter the second cache; and
delaying responding to a write request entering the second cache.
8. The method of claim 1 , wherein the second cache is formed from storage provided by a set of solid state disks (SSDs); and
wherein the method further comprises:
loading, as the first page, user data from storage provided by a set of hard disk drives (HDDs) into the second cache in response to an I/O request; and
wherein the set of SSDs and the set of HDDs reside in a same disk array.
9. A storage system, comprising:
a Non-Volatile Dual-In-Line Memory Module (NVDIMM);
a disk
a first cache;
a second cache; and
a controller configured to:
determine whether a number of I/O requests for a first page in the disk exceeds a first threshold;
in response to determining that the number exceeds the first threshold,
cache data in the first page to the first cache; and
store metadata associated with the first page in the NVDIMM; and
in response to receiving a write request for the cached first page,
cache the data in the first page to the second cache;
release space occupied by the data in the first page on the first cache;
write data related to the write request into the second cache; and
update the metadata associated with the first page in the NVDIMM.
10. The storage system of claim 9 , wherein the first cache comprises a solid-state disk with first endurance and the second cache comprises at least two solid-state disks with second endurance organized into a Redundant Array of Independent Disks (RAID), the second endurance being higher than the first endurance.
11. The storage system of claim 10 , wherein the first cache is a read-preference cache, and the second cache is a write cache.
12. The storage system of claim 9 , wherein updating the metadata associated with the first page comprises:
changing status of the first page to be dirty; and
modifying mapping information associated with the first page to indicate that the first page is mapped to the second cache.
13. The storage system of claim 9 , wherein the controller is further configured to:
in response to a number of cached pages on the second cache exceeding a second threshold, flush the cached pages to the disk; and
change status of the cached pages to clean page.
14. The storage system of claim 9 , wherein the controller is further configured to:
in response to a number of cached pages on the second cache exceeding a third threshold, limiting a number of write requests to enter the second cache.
15. The storage system of claim 14 , wherein limiting the number of write requests to enter the second cache comprises one of:
sending to an upper layer driver an indication to limit the number of write requests entering the second cache; and
delaying responding to a write request entering the second cache.
16. The storage system of claim 9 , wherein the storage system further comprises a set of hard disk drives (HDDs);
wherein the second cache is formed from storage provided by a set of solid state disks (SSDs);
wherein the set of SSDs and the set of HDDs reside in a same disk array of the storage system; and
wherein the controller is further configured to:
load, as the first page, user data from storage provided by the set of HDDs into the second cache in response to an I/O request.
17. A computer program product for storage management, the computer program product comprising:
a non-transitory computer readable medium encoded with computer-executable code, the code configured to enable the execution of:
determining whether a number of I/O requests for a first page in a disk of a storage system exceeds a first threshold;
in response to determining that the number exceeds the first threshold,
caching data in the first page to a first cache of the storage system; and
storing metadata associated with the first page in a Non-Volatile Dual-In-Line Memory Module (NVDIMM) of the storage system; and
in response to receiving a write request for the cached first page,
caching the data in the first page to a second cache of the storage system;
releasing space occupied by the data in the first page on the first cache;
writing data related to the write request into the second cache; and
updating the metadata associated with the first page in the NVDIMM.
18. The computer program product of claim 17 , wherein the first cache comprises a solid-state disk with first endurance and the second cache comprises at least two solid-state disks with second endurance organized into a Redundant Array of Independent Disks (RAID), the second endurance being higher than the first endurance.
19. The computer program product of claim 18 , wherein the first cache is a read-preference cache, and the second cache is a write cache.
20. The computer program product of claim 17 , wherein the second cache is formed from storage provided by a set of solid state disks (SSDs); and
wherein the code further configured to enable the execution of:
loading, as the first page, user data from storage provided by a set of hard disk drives (HDDs) into the second cache in response to an I/O request; and
wherein the set of SSDs and the set of HDDs reside in a same disk array.