Seamless data migration to the cloud
A data storage system migrates a device between a storage array and a cloud gateway based on monitored conditions such as access frequency. More particularly, both a logical volume and the associated data are migrated. The unique device ID (e.g. and without limitation the WWN or WWID) is maintained after migration so the migration is transparent to the host application. The device is deleted from the migration source after being moved to the migration target, thereby releasing resources such as memory, storage, processor cycles and bandwidth at the migration source. A multi-path IO driver in the host computer coordinates with a tiering program in the storage array and a monitoring program in the cloud gateway to manage migration of the logical volume.
1. An apparatus comprising:
a host computer comprising a processor, computer-readable memory and at least one host application;
a storage array comprising a plurality of computing nodes and persistent storage, each computing node comprising a processor and computer-readable memory, and managing a portion of the persistent storage;
a cloud gateway comprising a processor, computer-readable memory, and a translation program that translates between a first protocol implemented by the host computer and a second protocol implemented by cloud storage; and
program code stored on non-transitory computer-readable media that migrates data associated with a logical volume presented to the at least one host application with a first unique device ID between the storage array and the cloud gateway by causing creation of a new logical volume with a second unique device ID that is different than the first unique device ID, causing the data to be written to the new logical volume, and presenting the new logical volume to the at least one host application with the first unique device ID after moving the data, whereby the migration is transparent to the at least one host application.
2. The apparatus of claim 1 wherein the logical volume is presented by the storage array and wherein the program code comprises a multi-path input-output driver on the host computer that instructs the cloud gateway to create the new logical volume.
3. The apparatus of claim 2 comprising the program code moving the data to the new logical volume on the cloud gateway.
4. The apparatus of claim 3 comprising the program code deleting the logical volume from the storage array after moving the data to the new logical volume on the cloud gateway.
5. The apparatus of claim 4 comprising a multi-path input-output driver on the host computer and comprising the program code updating paths between the host computer and the logical volume.
6. The apparatus of claim 1 wherein the program code comprises a multi-path input-output driver on the host computer that monitors accesses to the logical volume and prompts the migration based on the monitored accesses.
7. The apparatus of claim 1 wherein the logical volume is presented by the storage array and wherein the program code comprises a tiering program on the storage array that monitors accesses to the logical volume and prompts the migration to the cloud gateway based on the monitored accesses.
8. The apparatus of claim 1 wherein the logical volume is presented by the cloud gateway and wherein the program code comprises a monitoring program on the cloud gateway that monitors accesses to the logical volume and prompts the migration to the storage array based on the monitored accesses.
9. The apparatus of claim 1 comprising the program code initiating the migration from the storage array to the cloud gateway based on an absence of accesses to the logical volume.
10. The apparatus of claim 1 comprising the program code initiating the migration from the cloud gateway to the storage array based on resumption of accesses to the logical volume.
11. A method comprising:
in a storage system comprising: a host computer comprising a processor, computer-readable memory and at least one host application; a storage array comprising a plurality of computing nodes and persistent storage, each computing node comprising a processor and computer-readable memory, and managing a portion of the persistent storage; and a cloud gateway comprising a processor, computer-readable memory, and a translation program that translates between a first protocol implemented by the host computer and a second protocol implemented by cloud storage:
migrating data associated with a logical volume presented to the at least one host application with a first unique device ID between the storage array and the cloud gateway by causing creation of a new logical volume with a second unique device ID that is different than the first unique device ID and causing the data to be written to the new logical volume; and
presenting the new logical volume to the at least one host application with the first unique device ID after moving the data, whereby the migration is transparent to the at least one host application.
12. The method of claim 11 wherein the logical volume is presented by the storage array and comprising a multi-path input-output driver on the host computer instructing the cloud gateway to create the new logical volume.
13. The method of claim 12 comprising moving the associated data to the new logical volume on the cloud gateway.
14. The method of claim 13 comprising deleting the logical volume from the storage array after moving the data to the new logical volume on the cloud gateway.
15. The method of claim 14 comprising updating paths between the host computer and the logical volume.
16. The method of claim 11 comprising a multi-path input-output driver on the host computer monitoring accesses to the logical volume and prompting the migration based on the monitored accesses.
17. The method of claim 11 wherein the logical volume is presented by the storage array and comprising a tiering program on the storage array monitoring accesses to the logical volume and prompting the migration to the cloud gateway based on the monitored accesses.
18. The method of claim 11 wherein the logical volume is presented by the cloud gateway and comprising a monitoring program on the cloud gateway monitoring accesses to the logical volume that are used to prompt the migration to the storage array.
19. The method of claim 11 comprising initiating the migration from the storage array to the cloud gateway based on an absence of accesses to the logical volume.
20. The method of claim 11 comprising initiating the migration from the cloud gateway to the storage array based on resumption of accesses to the logical volume.