Abstract: This invention is a system and a method for operating a storage server in a data network using a new architecture. The method of creating the partial block map allows the snapshot writes on a direct mapped file. The method of reading data or writing data to the file created in direct mapping state and later converted to partial mapping state responsive to a copy on first write request by a client allocates new indirect block when needed to store the reference to newly allocated data block. The method of reading data from or writing data to the file in partial mapping state involves checking the mapping bit to find if the indirect block is in direct mapping state.

Abstract: A self healing file system is designed for proactive detection and containment of faults, errors, and corruptions, in order to enable in place (online) and non-intrusive recovery. For proactive fault detection, the file system maintains certain per-block metadata of each file system block. The per-block metadata includes a redundancy check, and for file system data blocks, an inode identifier, and an offset of the file system data block in the file including the file system data block. The redundancy check is used to detect and mark bad file system blocks. The inode identifier and offset is used for validating connectivity of the file system blocks to the inodes, and for tracing bad blocks to files that contain the bad blocks.

Abstract: A container file system is built on a sparse metavolume for enhanced decoupling of logical storage from physical storage and for providing common supplementary storage services for iSCSI block access and for NFS or CIFS file system access. The container file system contains a production file system or iSCSI LUN and may also contain snapshot copies of the production file system or iSCSI LUN. The container file system manages storage space among the production file system or iSCSI LUN and its snapshot copies, and also improves fault containment. The sparse metavolume provides thin provisioning of the container file system. A slice map indicates whether or not each slice of logical storage in the sparse metavolume is provisioned with an associated configured slice of data storage.

Abstract: To recover from partial writes of metadata transactions to a file system log, a redundancy check is added to each log record. Upon re-boot of the file server, the file system is recovered by finding the last valid record in the log, and then replaying records from the log into the on-disk file system. The replay is terminated prior to the last valid record upon reaching any record with a bad redundancy check. A “fsck” is performed on the file system prior to granting client access to the file system only if the log recovery was terminated prior to the last valid record upon reaching a record with a bad redundancy check and the position of the records in the log indicates that this record with a bad redundancy check could not have been written to the log concurrently with the last valid record.

Abstract: A waste treatment plant (1) comprises an incinerator unit (30) and an autoclave unit (9) and operates such that steam for the autoclave is generated from heat in the incinerator and contaminated water from the autoclave is used to control the temperature in the incinerator, the contamination being destroyed in the process. Exhaust gas from the incinerator is used to reduce the water content of waste treated in the autoclave. Steam generated by the incinerator is available for plant washing operations, to wash bins that supplied waste to the plant before the bins are returned.