Vmware, Inc.

Jinyuan Li

Murali Vilayannur

Mayank Rawat

Irfan Ahmad

Austin Clements

Satyam B Vaghani

Daniel J Scales

Christopher Frost

Decentralized deduplication operations in a computer system employ a hash index that is a variant of a B+ tree to support both efficient sequential updates as well as efficient random updates. Sequential update is selected when deduplication is infrequently performed, such as on the order of days, and random update is selected when deduplication is performed more frequently, such as on the order of seconds. More frequent deduplication may be beneficial during periods when large amounts of temporary duplicate data are created, and the system may not have enough storage space to accommodate the temporary spike in demand.

Computer storage deduplication

A data center comprising plural computer hosts and a storage system external to said hosts is disclosed. The storage system includes storage blocks for storing tangibly encoded data blocks. Each of said hosts includes a deduplicating file system for identifying and merging identical data blocks stored in respective storage blocks into one of said storage blocks so that a first file exclusively accessed by a first host of said hosts and a second file accessed exclusively by a second host of said hosts concurrently refer to the same one of said storage blocks.

Decentralized deduplication operations in a virtualized computer environment having multiple storage devices employ a hash index for each storage device. When an image of a virtual machine is selected to be migrated from a source storage device to a destination storage device, hash values representing content of the storage blocks of the virtual machine are compared with hash entries of the destination hash index. Storage blocks of the virtual machine that have matching hash entries in the destination hash index are not transferred as part of the migration process so that the overall migration process can be accelerated.

Multiple servers sharing a distributed file system are used to perform copies of regions of a source file in parallel from a source storage unit to corresponding temporary files at a destination storage unit. These temporary files are then merged or combined into a single file at the destination storage unit in a way that preserves the inode structure and attributes of the source file. A substantial speedup is obtained by copying regions of the file in parallel.

Method and system for parallelizing data copy in a distributed file system

A method of acquiring a lock by a node, on a shared resource in a system of a plurality of interconnected nodes, is disclosed. Each node that competes for a lock on the shared resource maintains a list of locks currently owned by the node. A lock metadata is maintained on a shared storage that is accessible to all nodes that may compete for locks on shared resources. A heartbeat region is maintained on a shared resource corresponding to each node so nodes can register their liveness. A lock state is maintained in the lock metadata in the shared storage. A lock state may indicate lock held exclusively, lock free or lock in managed mode. If the lock is held in the managed mode, the ownership of the lock can be transferred to another node without a use of a mutual exclusion primitive such as the SCSI reservation.

Hybrid locking using network and on-disk based schemes

A network-based method for managing locks in a shared file system (SFS) for a group of hosts that does not require any configuration to identify a server for managing locks for the SFS. Each host in the group carries out the steps of checking a predetermined storage location to determine whether there is a host ID written in the predetermined location. If there is no host ID written in the predetermined location, the first host to notice this condition writes its host ID in the predetermined location to identify itself as the server for managing locks. If there is a host ID written in the predetermined location, the host ID of the server for managing locks is maintained in local memory. When the host needs to perform IO operations on a file of the SFS, it communicates with the server for managing locks over the network using the host ID of the server for managing locks to obtain a lock to the file.

Configuration-less network locking infrastructure for shared file systems

Metadata of a shared file in a clustered file system is changed in a way that ensures cache coherence amongst servers that can simultaneously access the shared file. Before a server changes the metadata of the shared file, it waits until no other server is attempting to access the shared file, and all I/O operations to the shared file are blocked. After writing the metadata changes to the shared file, local caches of the other servers are updated, as needed, and I/O operations to the shared file are unblocked.

Method and system for ensuring cache coherence of metadata in clustered file systems

A shared file system for a group of host computer systems is upgraded in-place in a manner that the shared file system can remain online and accessible to the host computer systems. Each host computer system first loads a new file system driver that is backward compatible with a driver that is currently used by them to interact with the file system. Second, one of the host computer systems acquires locks to file system management data structures of the file system, upgrades the file system management data structures, and upon completion thereof, notifies the other host computer system that the upgrade to the file system management data structures is complete.

Growing community of inventors

Mountain View, CA, United States of America

Jinyuan Li