230 results about "Clustered file system" patented technology

Methods for operating a network as a clustered file system is disclosed. The methods involve client load rebalancing, distributed Input and Output (I/O) and resource load rebalancing. Client load rebalancing refers to the ability of a client enabled with processes in accordance with the current invention to remap a path through a plurality of nodes to a resource. Distributed I/O refers to the methods on the network which provide concurrent input/output through a plurality of nodes to resources. Resource rebalancing includes remapping of pathways between nodes, e.g. servers, and resources, e.g. volumes/file systems. The network includes client nodes, server nodes and resources. Each of the resources couples to at least two of the server nodes. The method for operating comprising the acts of: redirecting an I/O request for a resource from a first server node coupled to the resource to a second server node coupled to the resource; and splitting the I/O request at the second server node into an access portion and a data transfer portion and passing the access portion to a corresponding administrative server node for the resource, and completing at the second server nodes subsequent to receipt of an access grant from the corresponding administrative server node a data transfer for the resource. In an alternate embodiment of the invention the methods may additionally include the acts of: detecting a change in an availability of the server nodes; and rebalancing the network by applying a load balancing function to the network to re-assign each of the available resources to a corresponding available administrative server node responsive to the detecting act.

A cluster of computer system nodes share direct read/write access to storage devices via a storage area network using a cluster filesystem. Version information about subsystems is acquired by a leader node when forming a cluster membership and distributed to all nodes in the cluster to enable proper messaging during operation. Access to files on the storage devices is arbitrated by the cluster filesystem using tokens. Upon detection of a change in location of the metadata server, client nodes waiting for a token are interrupted to check on the status of at least one of data and node availability. The cluster operating system maintains consistency of a mirrored data volume by automatically ensuring replication of a mirror leg while continuing to accept access requests to the mirrored data volume.

A system and method proxies data access commands across a cluster interconnect between storage appliances in a cluster. Each storage appliance activates two ports for data access, a local port for data access requests directed to clients of the storage appliance and a proxy port for data access requests directed to the partner storage appliance. Clients utilizing multi-pathing software may send data access requests to either the local port of the storage appliance or the proxy port of the storage appliance. The system and method improve high availability especially during a loss of connectivity due to non-storage appliance hardware failure.

A data management system or “DMS” provides data services to data sources associated with a set of application host servers. The data management system typically comprises one or more regions, with each region having one or more clusters. A given cluster has one or more nodes that share storage. When providing continuous data protection and data distribution, the DMS nodes create distributed object storage to provide the necessary real-time data management services. The objects created by the DMS nodes are so-called active objects. The distributed object store can be built above raw storage devices, a traditional file system, a special purpose file system, a clustered file system, a database, and so on. According to the present invention, the DMS active object store provides an indexing service to the active objects. In an illustrative embodiment, any object property that has a given attribute is indexed and, as a result, the attribute becomes searchable. The DMS provides hierarchical distributed indexing using index trees to facilitate searching in a highly efficient manner.

A method effectively preventing a requesting node from unfencing and mounting a file system subsequent to a failure in a cluster file system having a plurality of active nodes. The method comprising first upgrading one active node in the cluster to function as a cluster manager node. The cluster manager is in communication with all nodes. The cluster manager is assigned manager responsibilities, in part, comprising first receiving an active status request from the node requesting to mount a file system. The cluster manager first queries the quorum nodes to determine whether each node considers the cluster manager to still have cluster management responsibilities for the file system. If a majority of quorum nodes consider the cluster manager to still have cluster management responsibilities for the file system then the cluster manager responds to the requesting node's active status request. Thereafter, the requesting node proceeds with mounting the file system.

A method may involve: a node included in a cluster looking up a file in a metadata name cache; in response to a miss for the file in the metadata name cache, the node creating a metadata name cache entry for the file in the metadata name cache, where the metadata name cache entry includes a copy of a cookie associated with metadata allocated to the file; in response to a lock on the metadata changing state for the node, the node modifying the cookie associated with the metadata, where the lock changes state for the node in response to a request to a global lock manager for the lock on the metadata; and comparing the copy of the cookie stored in the metadata name cache entry to a current value of the cookie associated with the metadata to determine if the metadata name cache entry is valid.

The invention provides a cluster file system, which is characterized by comprising a directory server, a layout server cluster and a memory device array, wherein the directory server is used for storing directory metadata and providing a directory service; the layout server cluster is used for storing layout metadata and providing a layout service; and the memory device array is used for storing file content data. The invention also provides a corresponding file service method. The file service method comprises a file accessing step, namely, a client first accesses the directory server to acquire the directory information of a file, then accesses the layout sever to acquire the distribution information of the file content data on physical memory devices, and finally directly accesses the physical memory devices to acquire the data information. Compared with the prior art, the invention can further improve the expansion capability of the file cluster system, and is highly compatible and short in accessing delay.

A system and method for performing a distributed consistency check of a clustered file system. File system functions for loading an inode and/or buffer tree are modified so that in response to either of these functions being invoked, a consistency check is performed. The consistency check verifies both local consistency on a node of the clustered file and a distributed check across the nodes of the storage system

A method for avoiding directory conflicts across a file system having multiple nodes with one node representing a token manager. For each directory, at least one metanode responsible for directory updates. The method involving obtaining a name-based lock on a filename. Querying the token manager for a lock token. If a new token is obtained, sending a Remote Procedure Call (RPC) to the metanode to obtain matching directory entries, and caching the result of the RPC so that subsequent operations on that filename can be satisfied without additional messages sent to the metanode. Updating a cached directory block in memory by creating a new directory entry in the block or deleting an existing directory entry from the block. Information regarding the updating is sent to the metanode on one of: periodic schedule, a subsequent synchronization event, or when the name-based lock token is revoked.

The invention provides a method for ensuring the operation consistence of distributed metadata in a cluster file system in combination with a local log. The method comprises the following steps of: making a coordinator and a participant record a distributed metadata sub-operation update generated by using distributed metadata sub-operation in the local log as a local transaction, wherein the record of the distributed metadata sub-operation update includes a distributed transaction and/or a distributed metadata update; after the local transaction is submitted, writing the distributed transaction into a distributed log, and writing the distributed metadata update into a metadata disk; and before starting the distributed metadata sub-operation, forcibly submitting a local log transaction. According to the method, the local log is multiplexed effectively, and the implementation complexity of the distributed log is lowered; and moreover, cascading aborts can be avoided.

Systems and methods for providing more efficient handling of I/O requests for clustered file system data subject to data migration or the like. For instance, exemplary systems can more quickly determine if certain files on primary storage represent actual file data or stub data for recalling file data from secondary storage. Certain embodiments utilize a driver cache on each cluster node to maintain a record of recently accessed files that represent regular files (as opposed to stubs). A dual-locking process, using both strict locking and relaxed locking, maintains consistency between driver caches on different nodes and the data of the underlying clustered file system, while providing improved access to the data by the different nodes. Moreover, a signaling process can be used, such as with zero-length files, for alerting drivers on different nodes that data migration is to be performed and/or that the driver caches should be flushed.