Efficient transfers between tiers of a virtual storage system

1. A method comprising:

receiving, by a virtual controller in a virtual storage system whose components reside exclusively in a cloud computing environment, a request to write data to the virtual storage system, wherein the virtual controller includes a storage controller application executing on a cloud computing instance provided by a cloud services provider;

transforming, within staging memory provided by the first tier of storage of the virtual storage system, the data to generate transformed data, wherein the staging memory is an intermediate storage area used for receiving data from a virtual storage controller within the virtual storage system when transforming the data for subsequent storage within a second tier of storage in the virtual storage system, wherein the first tier of storage of the virtual storage systems includes block storage resources provided by the cloud services provider; and

migrating, from the staging memory in the first tier of storage to the second tier of storage that is more durable than the first tier of storage of the virtual storage system, at least a portion of the transformed data, wherein the second tier of storage of the virtual storage systems includes additional storage resources provided by the cloud services provider.

2. The method of claim 1 , wherein migrating the at least the portion of data stored within the staging memory is responsive to detecting a condition for transferring data between the staging memory to the durable data storage provided by the virtual storage system.

3. The method of claim 2 , wherein transforming the data includes detecting overwrites to existing data and creating a new object corresponding to the data.

4. The method of claim 2 , wherein controller logic configured to perform the transformation of the data is included within the one or more virtual drives of the staging memory.

5. The method of claim 4 , wherein the controller logic is further configured to perform receiving the request to write data.

6. The method of claim 2 , wherein transforming the data includes one or more of: deduplication, compression, or overwriting.

7. The method of claim 2 , wherein the staging memory includes multiple virtual drive servers.

8. The method of claim 7 , wherein the multiple virtual drive servers include respective local storage.

9. The method of claim 7 , wherein the multiple virtual drive servers provide block-level data storage.

10. The method of claim 2 , wherein the request to write data to the virtual storage system is received by one or more virtual controllers running within a virtual machine, a container, or a bare metal server.

11. The method of claim 2 , wherein staging memory is provided by multiple virtual drive servers that respectively include a both virtual controller and local memory.

12. The method of claim 2 , wherein the at least the portion of the data stored within the staging memory is deduplicated, encrypted, or compressed prior to migration from the staging memory to the durable data storage.

13. The method of claim 2 wherein the staging memory of the virtual storage system is characterized by a low read latency relative to the durable data storage provided by the cloud storage system.

14. A cloud-based virtual storage system whose components reside exclusively in a cloud computing environment, the cloud-based virtual storage system including:

one or more cloud-based virtual drives providing a cloud-based staging memory provided by the first tier of storage of the virtual storage system for storage operations, wherein the staging memory is an intermediate storage area used for receiving data from a storage controller within the virtual storage system when transforming the data for subsequent storage within a second tier of storage in the virtual storage system, wherein the first tier of storage of the virtual storage system includes block storage resources provided by a cloud services provider; and

one or more cloud-based virtual controllers, each virtual controller including a storage controller application executing in a cloud computing instance provided by the cloud services provider, wherein the one or more virtual controllers are configured to:

receive, by one or more virtual controllers in the virtual storage system, a request to write data to the virtual storage system;

transform, within staging memory provided by one or more virtual drives provided by the first tier of storage of the virtual storage system, the data to generate transformed data, wherein the staging memory provides transactional consistency and write acknowledgments, and wherein the second tier of storage includes virtual drives provided by virtual driver servers of the virtual storage system; and

migrate, from the staging memory in the first tier of storage to the second tier of storage that is more durable than the first tier of storage of the virtual storage system, wherein the second tier of storage of the virtual storage system includes additional storage resources provided by the cloud services provider, at least a portion of the transformed data.

15. The virtual storage system of claim 14 , wherein migrating the at least the portion of data stored within the staging memory is responsive to detecting a condition for transferring data between the staging memory to the durable data storage provided by the cloud services provider.

16. The virtual storage system of claim 14 , wherein transforming the data includes detecting overwrites to data that reduce an amount of data that is migrated to the durable data storage.

17. The virtual storage system of claim 14 , wherein controller logic configured to perform the transformation of the data is included within the one or more virtual drives of the staging memory.

18. The virtual storage system of claim 17 , wherein the controller logic is further configured to perform receiving the request to write data.