Abstract: A method is described. The method includes receiving logs from multiple connector nodes, each of the logs having entries that describe changes made to a file system at its respective one of the connector nodes. The method includes constructing a directed acyclic graph (DAG) from the logs' respective entries, the DAG comprising nodes connected by flows, the nodes describing actions made to directories and files of the file system, wherein, a flow of the flows connects a subset of the nodes that describe actions made to a particular directory or file of the file system. The method includes removing one or more irrelevant nodes from the DAG. The method includes applying actions described by remaining nodes of the DAG to an object storage system having respective objects for directories and files of the file system.

Abstract: A method is described. The method includes receiving a PUT operation request from a user to store a data item. The method also includes sending S PUT commands to S working storage devices to respectively store S replicas or extents for the data item. The method also includes confirming to the user that the data item was stored after receiving X acknowledgments from the S working devices where X<S. The method also includes, in response to a crash, reading non volatile records for the S working devices that record successful stores performed by the S working devices having corresponding acknowledgements that were not responded to. The method also includes recognizing from the non volatile records that less than S of the S replicas or extents were successfully stored into the S working devices. The method includes causing those of the S replicas or extents that were not successfully stored to be stored to complete the PUT operation.

Abstract: A method is described. The method includes queuing an entry in a queue that identifies an inode that has been changed in an active storage system. The entry further describes a time in the future. The method includes processing the entry upon the time in the future being reached. The processing of the entry includes comparing respective content values maintained for different regions of the inode within the active storage system and a replicate storage system. The method further includes comparing content of those of the regions having different content values as between the active storage system and the replicate storage system. The method further includes updating those regions in the replicate storage system to reflect those regions within the active storage system based on the comparing, and, updating the respective content values of those regions in the replicate storage system.

Abstract: A method is described. The method includes queuing an entry in a queue that identifies an inode that has been changed in an active storage system. The entry further describes a time in the future. The method includes processing the entry upon the time in the future being reached. The processing of the entry includes comparing respective content values maintained for different regions of the inode within the active storage system and a replicate storage system. The method further includes comparing content of those of the regions having different content values as between the active storage system and the replicate storage system. The method further includes updating those regions in the replicate storage system to reflect those regions within the active storage system based on the comparing, and, updating the respective content values of those regions in the replicate storage system.

Abstract: A method is described. The method includes receiving logs from multiple connector nodes, each of the logs having entries that describe changes made to a file system at its respective one of the connector nodes. The method includes constructing a directed acyclic graph (DAG) from the logs' respective entries, the DAG comprising nodes connected by flows, the nodes describing actions made to directories and files of the file system, wherein, a flow of the flows connects a subset of the nodes that describe actions made to a particular directory or file of the file system. The method includes removing one or more irrelevant nodes from the DAG. The method includes applying actions described by remaining nodes of the DAG to an object storage system having respective objects for directories and files of the file system.