Storage unit selection of memory devices used for distributed storage network memory
A storage unit in a distributed storage network (DSN) transmits resource availability information to a managing unit. The resource availability information includes information indicating a number of available memory devices of the storage unit that are available to be used for storage of encoded data slices. The storage unit receives resource assignment information determined by the managing unit. The resource assignment information includes one or more dispersal parameters, information identifying a set of storage units to be included in a newly instantiated DSN memory, and a DSN address range assigned to the storage unit for use in the newly instantiated DSN memory. The storage unit selects particular available memory devices of the storage unit to assign to the newly instantiated DSN memory. The selection is based on the resource assignment information.
1. A method for use in a distributed storage network (DSN), the method comprising:
transmitting resource availability information from a storage unit to a managing unit, the resource availability information including information indicating a number of available memory devices of the storage unit that are available to be used for storage of encoded data slices;
receiving, at the storage unit, resource assignment information determined by the managing unit, the resource assignment information including:
one or more dispersal parameters;
information identifying a set of storage units to be included in a newly instantiated DSN memory;
a DSN address range assigned to the storage unit for use in the newly instantiated DSN memory; and
selecting, by the storage unit, particular available memory devices of the storage unit to assign to the newly instantiated DSN memory based on the resource assignment information.
2. The method of claim 1 , further comprising:
allocating, by the storage unit, sub-DSN address ranges to the particular available memory devices.
3. The method of claim 1 , wherein:
the one or more dispersal parameters are selected by the managing unit to satisfy a performance threshold associated with storage of the encoded data slices, subject to a constraint requiring a pillar width associated with the encoded data slices to be no larger than the number of available memory devices.
4. The method of claim 1 , wherein:
the one or more dispersal parameters are selected to achieve a target mean time to data loss and a target write availability.
5. The method of claim 2 , further comprising:
allocating the sub-DSN address ranges to the particular available memory devices based, at least in part, on utilization of the particular available memory devices.
6. The method of claim 2 , wherein:
the sub-DSN address ranges are allocated based on the one or more dispersal parameters.
7. The method of claim 2 , wherein:
the sub-DSN address ranges are determined by dividing the DSN address range assigned to the storage unit by the number of available memory devices of the storage unit.
8. A computing device for use in a distributed storage network (DSN), the computing device comprising:
a processor;
memory operably associated with the processor and storing a program of instructions, upon execution by the processor, causing the processor to implement a storage unit configured to:
transmit resource availability information to a managing unit, the resource availability information including information indicating a number of available memory devices of the storage unit that are available to be used for storage of encoded data slices;
receive resource assignment information determined by the managing unit, the resource assignment information including:
one or more dispersal parameters;
information identifying a set of storage units to be included in a newly instantiated DSN memory;
a DSN address range assigned to the storage unit for use in the newly instantiated DSN memory; and
select particular available memory devices of the storage unit to assign to the newly instantiated DSN memory based on the resource assignment information.
9. The computing device of claim 8 , the storage unit further configured to:
allocate sub-DSN address ranges to the particular available memory devices.
10. The computing device of claim 8 , wherein:
the one or more dispersal parameters are selected by the managing unit to satisfy a performance threshold associated with storage of the encoded data slices, subject to a constraint requiring a pillar width associated with the encoded data slices to be no larger than the number of available memory devices.
11. The computing device of claim 8 , wherein:
the one or more dispersal parameters are selected to achieve a target mean time to data loss and a target write availability.
12. The computing device of claim 9 , the storage unit further configured to:
allocate the sub-DSN address ranges to the particular available memory devices based, at least in part, on utilization of the particular available memory devices.
13. The computing device of claim 9 , wherein:
the sub-DSN address ranges are allocated based on the one or more dispersal parameters.
14. The computing device of claim 9 , wherein:
the sub-DSN address ranges are determined by dividing the DSN address range assigned to the storage unit by the number of available memory devices of the storage unit.
15. A distributed storage network (DSN) comprising:
a plurality of storage units logically organized into DSN memories, each of the plurality of storage units including memory devices configured to store error encoded data slices;
a managing unit coupled to the plurality of storage units;
each storage unit including a processor and associated memory configured to:
transmit resource availability information to the managing unit, the resource availability information including information indicating a number of available memory devices of the storage unit that are available to be used for storage of encoded data slices;
receive resource assignment information determined by the managing unit, the resource assignment information including:
one or more dispersal parameters;
information identifying a set of storage units to be included in a newly instantiated DSN memory;
a DSN address range assigned to the storage unit for use in the newly instantiated DSN memory; and
select particular available memory devices of the storage unit to assign to the newly instantiated DSN memory based on the resource assignment information.
16. The distributed storage network (DSN) of claim 15 , each storage unit further configured to:
allocate sub-DSN address ranges to the particular available memory devices.
17. The distributed storage network (DSN) of claim 15 , wherein:
the one or more dispersal parameters are selected by the managing unit to satisfy a performance threshold associated with storage of the encoded data slices, subject to a constraint requiring a pillar width associated with the encoded data slices to be no larger than the number of available memory devices.
18. The distributed storage network (DSN) of claim 16 , each storage units further configured to:
allocate the sub-DSN address ranges to the particular available memory devices based, at least in part, on utilization of the particular available memory devices.
19. The distributed storage network (DSN) of claim 16 , each storage units further configured to:
determine the sub-DSN address ranges by dividing the DSN address range assigned to the storage unit by the number of available memory devices of the storage unit.