Emc Corporation

Emc IP Holding Company LLC

John Michael Hayden

Jean-Pierre Bono

Sairam Veeraswamy

Sachin Mullick

Xiaoye Jiang

Milena Bergant

Daniel Zhu

Roy E Clark

Himabindu Tummala

Uresh K Vahalia

Robert W Beauchamp

Morgan A Clark

Robert C Solomon

Humberto Rodriguez

Santosh Pasula Reddy

Stephen J Todd

Philippe Armangau

Frederic Corniquet

Douglas A Wood

Jiannan Zheng

Ajay Potnis

Christopher H Stacey

Hongliang Tang

Saurabh Ramchandra Godbole

John A Hilliar

Sairam Iyer

Hongmei Wang

Pascal Donette

Aju John

Daniel J Sledz

Brett Johnson

David M Kipp

Mrinalini Chavan

Implementations are provided herein for establishing a failover cluster in a distributed file system that upon the occurrence of failover event, allows clients to actively migrate during ongoing file system activity from a source cluster to a target cluster without having to unmount an NFS export from the source cluster and remount the NFS export on the target cluster. Upon the occurrence of a failover event, clients can be rerouted to a target cluster that contains mirrored copies of the data the client was expecting to be stored on the original source cluster. However, in attempting to access the data, without unmounting and remounting an export, the client will continue to reference source cluster FSID and LIN identifiers when making NFS calls to the target cluster. Thus, implementations are provided herein for translating the requests of an NFS client on a target cluster after a failover event has occurred. A client can make NFS calls using FSID and LIN information of the original source cluster, and that information can be translated, e.g., through a reverse LIN map, to the unique LIN's of the target cluster, such that any failover migration of the client is transparent to the client.

NFS cluster failover

A method and system for use in managing data objects is disclosed. In at least one embodiment, the method and system comprises based on at least one policy set, determining that a data object stored on a first device is eligible for mobile enablement and a level of mobile enablement for the data object; mobile enabling the data object, wherein mobile enabling the data object comprises causing a mobile data storage tier associated with the first device to include the data object; and providing access to the data object to a second device, wherein access is defined by the level of mobile enablement.

Managing data objects

A client computer migrates data objects from a first data store employing a flat namespace to a second data store employing a hierarchical directory-based file system. File storing includes (1) generating a data object (for user data file) and an object identifier which is returned to an application for use in retrieving the user data file; (2) mapping the object identifier to originate a subdirectory name; and (3) sending a write request to the file system to create the named subdirectory and store the data object therein. File retrieving includes (4) sending a read request including the object identifier to the first data store; (5) extracting a user data file from a received data object and returning it to the application; and (6) performing the steps of the file storing to store the data object at the second data store, completing the migration of the data object.

Client-based migrating of data from content-addressed storage to file-based storage

A file is initially created to have metadata and a data block allocation for direct mapping without access to any indirect blocks. Therefore file access performance is increased because the direct mapping eliminates delay otherwise caused by fetching one or more indirect blocks. When needed, the functionality enabled by indirect mapping is provided by creating an indirect mapping for the file and then accessing the file using the indirect mapping. When the functionality enabled by the indirect mapping is no longer needed, the file is reorganized to a direct mapping and then accessed using the direct mapping. For example, a container file for a network attached SCSI LUN is created and accessed without a performance degradation until conversion to an indirect mapping occurs automatically and seamlessly upon activation of a supplementary storage service such as a file-based snapshot copy and replication facility.

Direct or indirect mapping policy for data blocks of a file in a file system

A method, computer program product, and cache management system for receiving an indication of a data portion update within an electromechanical storage system. Information concerning the data portion update is provided to at least one proprietary, solid-state, non-volatile, cache memory system. The proprietary, solid-state, non-volatile, cache memory system is associated with at least a first of a plurality of computing devices and is not associated with at least a second of the plurality of computing devices.

Cache management system and method

A data storage server is programmed with common software modules for management, version control, and scheduling of replication of data storage objects of multiple data storage object types. The multiple data storage object types include iSCSI LUNs, file systems, virtual servers, directories, and files. The version control determines if two data storage objects are the same or have a common base so that only a difference needs to be transmitted for replication or restoration. The scheduler controls the timing of snapshot creation and deletion, and replication transmission to one or more remote destinations. The scheduler may ensure that a replica of a data storage object is out-of-sync with the original of the data storage object by no more than a specified amount of time.

Data storage server having common replication architecture for multiple storage object types

A file server provides access to a file system built on a logical volume of data storage. The file system includes multiple cylinder groups of file system blocks, and the logical volume includes slices of the cylinder groups. The file server has a storage reorganizer for identifying allocated file system blocks in a selected slice, and evacuating the identified allocated file system blocks from the selected slice. The selected slice is evacuated by reverse mapping each identified allocated block to identify a file to which the identified allocated block is allocated, allocating a new block in another slice, copying data from the identified allocated block to the new block, and substituting the new block for the identified allocated block in the file.

Reclaiming storage from a file system in a file server

In response to detection of an error in a filesystem file of a virtually provisioned volume or iSCSI LUN host, where the filesystem file is represented in a container filesystem, a Media Sector Error is returned at the virtual volume layer or the virtual iSCSI layer. The error may be a file allocation correction because of a shared block detected by a filesystem check of the container filesystem. The container may flag the shared block to prompt return of the Media Sector Error in response to attempted access of the block by the host. The host is operative to process the Media Sector Error like a storage subsystem Read Media Error, such that the flagged block is overwritten by the host to clear the error.

Virtually provisioned volume recovery

This invention is a system and a method for performing an I/O in a virtual data storage environment using a new architecture. The system of performing an I/O includes a mapping client integrated into a client of the storage server which in communication with the mapping server included in the storage server retrieves the mapping of the special data sharing storage objects and caches the shared objects in the data cache include in the client environment. The method of accessing the data sharing storage objects by one or more applications running on a client reduces the number of I/O on the storage objects by caching the storage objects in the data cache and bringing the knowledge of data sharing into the client environment.

Shared storage I/O elimination through mapping client integration into a hypervisor

Described are techniques for correcting at least some inconsistencies in a file system accessed by at least one client, while maintaining the file system online. A file system checking utility is executed on the file system to detect and create corrections for inconsistencies in the file system. The file system is updated to include at least some corrections. Also described is a computer system comprising a file system accessed by a client. A file system checking utility is executed on the file system to detect at least some inconsistencies in the file system, and to create a corrected version of the file system that includes corrections to correct for at least some of the detected inconsistencies. A report is created. The file system is not updated with the corrected version unless the proposed corrections are approved. The file system checking utility may be periodically scheduled for execution.

Detection of inconsistencies in a file system

Storage tiering uses file system awareness of storage class for storage allocation or migration of a storage object from one class of storage to another. For example, the storage object is a production file system, a logical unit number (LUN) of storage, or a snapshot copy of the production file system or LUN. Each storage class may comprise a different back-end disk type, such as Fiber Channel, ATA, etc. Storage allocation or migration is based on storage class to implement a storage policy, such as: (a) move snapshots off the class of storage of the production object and onto a different class of storage; (b) direct new writes to a specified class of storage; or (c) writes targeting a particular storage object are targeted to a particular class of storage.

Tiering storage between multiple classes of storage on the same container file system

An apparatus and method are described for defining, maintaining and displaying a checkpoint result set to facilitate identification of desirable checkpoints during system recovery. The checkpoint result set may be mapped to a user-customizable namespace. The user customizes the namespace by selecting one or more characteristics of desirable file system checkpoints. Being able to customize the namespace in this manner enables the user to be provided a more streamlined checkpoint result set in the event of data corruption. As a result an appropriate checkpoint can be more quickly selected for use in recovery.

User customizable CVFS namespace

When a directory tree is migrated from a source file system to a target file system, the directories of the directory tree are retained in the source file system, and handle translation entries are substituted for the regular data files of the directory tree in the source file system. The handle translation entries provide new file handles for the regular data files when the source file system is accessed with old file handles of the regular data files. For example, each handle translation entry includes the old file handle, a file system identifier, and the new file handle. The old file handle provides verification of the file handle being used for accessing the handle translation entry, and the file system identifier identifies the target file system in which the new file handle is valid.

File handle banking to provide non-disruptive migration of files

Client computers, a namespace server, and file servers are linked in a data network so that the namespace server provides the clients with NFS or CIFS access to a virtual file system including files stored in the file servers, and also provides migration of files between the file servers in a fashion transparent to the client access using NFS or CIFS. The client computers and storage arrays storing the file data are also linked in a storage area network so that the clients have high speed block access to the file data using a file mapping protocol. The namespace server redirects a metadata access request in the file mapping protocol from a client to the appropriate file server when the file is not being migrated, and otherwise denies the metadata access request when the file is being migrated so that the client reverts to NFS or CIFS access.

Growing community of inventors

Holliston, MA, United States of America

John Michael Hayden