A method, comprising: performing, by one or more computing devices: directing, with a control system and in response to a network status comprising a network partition and/or a large amount of network traffic, a storage node of a plurality of storage nodes maintaining replicas of a data volume to cease maintaining a replica of the data volume, to cause the data volume maintained at the plurality of storage nodes to enter a reduced durability state; determining, after the directing, that the storage node of the plurality of storage nodes maintaining replicas of the data volume is unavailable for replication, wherein write requests received for the data volume are completed at the plurality of storage nodes in order to perform replication for the data volume, wherein write requests are acknowledged as complete when complete; in response to said determining that the storage node is unavailable, processing subsequently received write requests for the data volume according to a reduced durability state for the data volume such that replication for the data volume is disabled for the storage node, comprising: for each of the subsequently received write requests for the data volume: completing the subsequently received write request at one or more storage nodes of the plurality of storage nodes available for replication, wherein the write request is completed at a fewer number of storage nodes than the plurality of storage nodes; and in response to completing the write request, acknowledging the write request as complete; determining that replication for the data volume is to be enabled for the storage node or another storage node; and in response to determining that replication for the data volume is to be enabled, enabling replication for the storage node or the other storage node such that additional write requests are completed at the storage node or the other storage node prior to acknowledging the additional write requests as complete. directing, with a control system and in response to a network status comprising a network partition and/or a large amount of network traffic, a storage node of a plurality of storage nodes maintaining replicas of a data volume to cease maintaining a replica of the data volume, to cause the data volume maintained at the plurality of storage nodes to enter a reduced durability state; determining, after the directing, that the storage node of the plurality of storage nodes maintaining replicas of the data volume is unavailable for replication, wherein write requests received for the data volume are completed at the plurality of storage nodes in order to perform replication for the data volume, wherein write requests are acknowledged as complete when complete; in response to said determining that the storage node is unavailable, processing subsequently received write requests for the data volume according to a reduced durability state for the data volume such that replication for the data volume is disabled for the storage node, comprising: for each of the subsequently received write requests for the data volume: completing the subsequently received write request at one or more storage nodes of the plurality of storage nodes available for replication, wherein the write request is completed at a fewer number of storage nodes than the plurality of storage nodes; and in response to completing the write request, acknowledging the write request as complete; completing the subsequently received write request at one or more storage nodes of the plurality of storage nodes available for replication, wherein the write request is completed at a fewer number of storage nodes than the plurality of storage nodes; and in response to completing the write request, acknowledging the write request as complete; determining that replication for the data volume is to be enabled for the storage node or another storage node; and in response to determining that replication for the data volume is to be enabled, enabling replication for the storage node or the other storage node such that additional write requests are completed at the storage node or the other storage node prior to acknowledging the additional write requests as complete.