Accessing data in multiple dispersed storage networks

1. A method comprises:

for each of a plurality of dispersed storage networks (DSNs) in a computing system network, identifying sets of dispersed storage (DS) units, wherein a set of the sets of DS unit stores an error coded data file;

identifying a reference entity within the computing system network;

for each of the plurality of DSNs:

determining first data access performance information between the reference entity and a first one of the sets of DS units; and

determining second data access performance information between the reference entity and a second one of the sets of DS units, wherein determining each of the first and second data access performance information includes:

determining a likelihood of retrieving a decode threshold number of encoded data slices of at least a portion of the error coded data file;

determining data retrieval access latency for retrieving the decode threshold number of encoded data slices; and

generating the data access performance information based on the likelihood of retrieving the decode threshold number of encoded data slices and the data retrieval access latency; and

storing the first and second data access performance information for each of the plurality of DSNs to produce system data access performance information.

2. The method of claim 1 further comprises:

identifying a second reference entity within the computing system network;

for each of the plurality of DSNs:

determining third data access performance information between the second reference entity and the first one of the sets of DS units; and

determining fourth data access performance information between the second reference entity and the second one of the sets of DS units; and

storing the third and fourth data access performance information for each of the plurality of DSNs as part of the system data access performance information.

3. The method of claim 1 , wherein determining the data access performance information comprises:

determining a likelihood of storing a write threshold number of encoded data slices of the at least a portion of the error coded data file;

determining data write access latency for storing the write threshold number of encoded data slices; and

generating the data access performance information based on the likelihood of storing the write threshold number of encoded data slices and the data write access latency.

4. The method of claim 1 further comprises:

updating previous data access performance information with current data access performance information to produce the data access performance information.

5. The method of claim 1 further comprises:

outputting the data access performance information to an accessing device such that the accessing device determines specific data access performance information based on the reference entity's data access performance information.

6. A computer comprises:

an interface;

a memory; and

a processing module operable to:

for each of a plurality of dispersed storage networks (DSNs) in a computing system network, identify sets of dispersed storage (DS) units, wherein a set of the sets of DS unit stores an error coded data file;

identify a reference entity within the computing system network;

for each of the plurality of DSNs:

determine first data access performance information between the reference entity and a first one of the sets of DS units; and

determine second data access performance information between the reference entity and a second one of the sets of DS units, wherein the processing module further functions to determine each of the first and second data access performance information by:

determining a likelihood of retrieving a decode threshold number of encoded data slices of at least a portion of the error coded data file;

determining data retrieval access latency for retrieving the decode threshold number of encoded data slices; and

generating the data access performance information based on the likelihood of retrieving the decode threshold number of encoded data slices and the data retrieval access latency; and

store, in the memory, the first and second data access performance information for each of the plurality of DSNs to produce system data access performance information.

7. The computer of claim 6 , wherein the processing module further functions to:

identify a second reference entity within the computing system network;

for each of the plurality of DSNs:

determine third data access performance information between the second reference entity and the first one of the sets of DS units; and

determine fourth data access performance information between the second reference entity and the second one of the sets of DS units; and

store, in the memory, the third and fourth data access performance information for each of the plurality of DSNs as part of the system data access performance information.

8. The computer of claim 6 , wherein the processing module further functions to determine the data access performance information by:

determining a likelihood of storing a write threshold number of encoded data slices of the at least a portion of the error coded data file;

determining data write access latency for storing the write threshold number of encoded data slices; and

generating the data access performance information based on the likelihood of storing the write threshold number of encoded data slices and the data write access latency.

9. The computer of claim 6 , wherein the processing module further functions to:

update, in the memory, previous data access performance information with current data access performance information to produce the data access performance information.

10. The computer of claim 6 , wherein the processing module further functions to:

output, via the interface, the data access performance information to an accessing device such that the accessing device determines specific data access performance information based on the reference entity's data access performance information.