Methods and apparatus for providing hypervisor level data services for server virtualization
A data center for data backup and replication, including a pool of multiple storage units for storing a journal of I/O write commands issued at respective times, wherein the journal spans a history window of a pre-specified time length, and a journal manager for dynamically allocating more storage units for storing the journal as the journal size increases, and for dynamically releasing storage units as the journal size decreases.
1. A method for data backup and replication, comprising:
transmitting, by a protected site computing device, a write request to a protected site disk, the write request intercepted by a recovery site computing device, interception of the write request causing the recovery site computing device to:
select a variable size storage unit from a plurality of variable size storage units to store new data of the write request, each of the variable size storage units comprising one or more variable size data chunks and each of the one or more variable size data chunks corresponding to a window of time;
set a size of the variable size storage unit using at least one of the one or more variable size data chunks based on a size of the new data of the write request; and
store the new data in the variable size storage unit of a journal at the recovery site computing device.
2. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
compare the size of the new data of the write request to a predesignated size; and
set the size of the variable size storage unit, responsive to a determination that the size of the new data of the write request exceeds the predesignated size.
3. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine that the write request specifies addition of the new data to the variable size storage unit that would cause the plurality of variable size storage units to exceed a maximum journal size; and
remove, responsive to determining that the addition of the new data exceeds the maximum journal size, data from the plurality of variable size storage units.
4. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine that a time between a previous write request and the write request is within a maintenance history time window; and
store, responsive to determining that the time between the previous write request and the write request is within the maintenance history time window, the new data of the write request in the variable size storage unit of the journal at the recovery site computing device.
5. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
move data from the plurality of variable size storage units to a recovery disk, responsive to determining that that write request specifies addition of the new data to the variable size storage unit that would cause the variable size storage unit to exceed a predesignated size;
remove the data from the plurality of variable size storage units.
6. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine a time window for the write request;
identify the variable size storage unit as corresponding to the time window for the write request; and
select the variable size storage unit from the plurality of variable size storage units to store the new data of the write request, responsive to identification the variable size storage unit as corresponding to the time window for the write request.
7. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine that none of the plurality of variable size storage units are available for storing the new data of the write request;
move data from the plurality of variable size storage units to a recovery disk, responsive to the determination that none of the plurality of variable size storage units are available for storing the new data of the write request.
8. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine that a priority of the write request from the protected site computing device supersedes a priority of a write request from a second protected site computing device; and
select the variable size storage unit from the plurality of variable size storage units to store the new data of the write request, responsive to the determination that the priority of the write request from the protected site computing device supersedes the priority of the write request from the second protected site computing device.
9. The method of claim 1 , comprising:
transmitting, by the protected site computing device, the write request to the protected site disk, the write request intercepted by the recovery site computing device, the interception of the write request causing the recovery site computing device to:
determine a time window for the write request;
identify the variable size storage unit as corresponding to the time window for the write request;
determine that the variable size storage unit includes data; and
move the data from the variable size storage unit to a recovery disk.
10. The method of claim 1 , comprising:
compressing, by the protected site computing device, the new data of the write request based on a specified compression format.
11. A system for data backup and replication, comprising:
a protected site computing device that transmits a write request to a protected site disk, the write request intercepted by a recovery site computing device, interception of the write request causing the recovery site computing device to:
select a variable size storage unit from a plurality of variable size storage units to store new data of the write request, each of the variable size storage units comprising one or more variable size data chunks and each of the one or more variable size data chunks corresponding to a window of time;
set a size of the variable size storage unit using at least one of the one or more variable size data chunks based on a size of the new data of the write request; and
store, the new data in the variable size storage unit of a journal at the recovery site computing device.
12. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
compare the size of the new data of the write request to a predesignated size; and
set the size of the variable size storage unit, responsive to a determination that the size of the new data of the write request exceeds the predesignated size.
13. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine that the write request specifies addition of the new data to the variable size storage unit that would cause the plurality of variable size storage units to exceed a maximum journal size; and
remove, responsive to the determination that the write request specifies the addition of the new data that would cause the plurality of variable size storage units to exceed the maximum journal size, data from the plurality of variable size storage units.
14. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine that a time between a previous write request and the write request is within a maintenance history time window; and
store, responsive to the determination that the time between the previous write request and the write request is within the maintenance history time window, the new data of the write request in the variable size storage unit of the journal at the recovery site computing device.
15. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
move data from the plurality of variable size storage units to a recovery disk, responsive to a determination that that write request specifies addition of the new data to the variable size storage unit that would cause the variable size storage unit to exceed a predesignated size; and
remove the data from the plurality of variable size storage units.
16. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine a time window for the write request;
identify the variable size storage unit as corresponding to the time window for the write request; and
select the variable size storage unit from the plurality of variable size storage units to store the new data of the write request, responsive to the identification of the variable size storage unit as corresponding to the time window for the write request.
17. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine that none of the plurality of variable size storage units are available to store the new data of the write request;
move data from the plurality of variable size storage units to a recovery disk, responsive to the determination that none of the plurality of variable size storage units are available to store the new data of the write request.
18. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine that a priority of the write request from the protected site computing device supersedes a priority of a write request from a second protected site computing device; and
select the variable size storage unit from the plurality of variable size storage units to store the new data of the write request, responsive to the determination that the priority of the write request from the protected site computing device supersedes the priority of the write request from the second protected site computing device.
19. The system of claim 11 , wherein the interception of the write request causes the recovery site computing device to:
determine a time window for the write request;
identify the variable size storage unit as corresponding to the time window for the write request;
determine that the variable size storage unit includes data; and
move the data from the variable size storage unit to a recovery disk.
20. The system of claim 11 , wherein the protected site computing device compresses the new data of the write request based on a specified compression format.