Managing unavailable storage in a dispersed storage network

A computer readable memory device comprises:

• at least one memory section that stores operational instructions that, when executed by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), causes the one or more computing devices to:
• identify a data object of a group of data objects for storage in the DSN;
• determine micro slice encoding parameters for the encoding the data object, wherein the data object is segmented into a plurality of data segments, wherein a data segment is encoded into a plurality of encoded micro slices in accordance with micro slice encoding parameters, wherein a micro slice decode threshold number of encoded micro slices of the plurality of encoded micro slices is needed to recover the data segment;
• dispersed storage error encode the data segment into a set of encoded micro slices in accordance with micro slice encoding parameters;
• identify a set of distributed storage (DS) units for storing the set of encoded micro slices;
• generate a set of meta-slices from the set of encoded micro slices, wherein each meta-slice is generated according to dispersal parameters;
• determine whether one or more DS units of the set of DS units is available to store each meta-slice of the set of meta-slices;
• determine a mapping scheme for storing the set of encoded micro slices;
• map each meta-slice associated with a DS unit available to store the encoded micro slices of the set of encoded micro slices in accordance with the mapping scheme;
• transmit each meta-slice associated with a DS unit available to store the encoded micro slices of the set of encoded micro slices to the one or more DS units of the set of DS units that are available to store the encoded micro slices;
• and
• in response to a determination that one or more DS units of the set of DS units is not available to store the encoded micro slices, transmit each meta-slice associated with a DS unit not available to store the encoded micro slices of the set of encoded micro slices to one of the DS units available to store the encoded micro slices of the set of encoded micro slices.

A computing device of a group of computing devices of a dispersed storage network (DSN), the computing device comprises:

• an interface;
• a local memory;
• and
• a processing module operably coupled to the interface and the local memory, wherein the processing module functions to:
• identify a data object of a group of data objects for storage in the DSN;
• determine micro slice encoding parameters for the encoding the data object, wherein the data object is segmented into a plurality of data segments, wherein a data segment is encoded into a plurality of encoded micro slices in accordance with micro slice encoding parameters, wherein a micro slice decode threshold number of encoded micro slices of the plurality of encoded micro slices is needed to recover the data segment;
• dispersed storage error encode the data segment into a set of encoded micro slices in accordance with micro slice encoding parameters;
• identify a set of distributed storage (DS) units for storing the set of encoded micro slices;
• generate a set of meta-slices from the set of encoded micro slices, wherein each meta-slice is generated according to dispersal parameters;
• determine whether one or more DS units of the set of DS units is available to store each meta-slice of the set of meta-slices;
• determine a mapping scheme for storing the set of encoded micro slices;
• map each meta-slice associated with a DS unit available to store the encoded micro slices of the set of encoded micro slices in accordance with the mapping scheme;
• transmit each meta-slice associated with a DS unit available to store the encoded micro slices of the set of encoded micro slices to the one or more DS units of the set of DS units that are available to store the encoded micro slices;
• and
• in response to a determination that one or more DS units of the set of DS units is not available to store the encoded micro slices, transmit each meta-slice associated with a DS unit not available to store the encoded micro slices of the set of encoded micro slices to one of the DS units available to store the encoded micro slices of the set of encoded micro slices.