Emc IP Holding Company LLC

Emc Corporation

Qi Mao

Ye Zhang

William C Davenport

Jean-Pierre Bono

Yining Si

Chao Zheng

Yingchao Zhou

Xianlong Liu

Alexander Daniel

Pu Wang

Xiangping Chen

Ahsan Rashid

Alexander S Mathews

Morgan A Clark

Ruiling Dou

Kamakshi Viswanadha

Michael D Schouten

Yunfei Chen

Changyong Yu

Henry Hao Fang

Kent J Costa

Chang Yong Yu

Alex Zhongbing Yang

Gyanesh Kumar Choudhary

Hansi Wu

Kenny Zhou

Chuangxian Wei

A data storage system operates a file system as a thinly provisioned file system having a host-visible virtual space and a smaller allocated space of underlying physical storage from a pool. The file system applies formatting to the allocated space and utilizes formatted allocated space for storing host files. The file system receives a file I/O request that requires increasing the allocated space of the file system, and in response (1) obtains an extent of physical storage from the pool and adds it to the file system as added allocated space, and (2) formats an initial portion of the added allocated space and satisfies the file I/O request using the formatted initial portion. Over a subsequent period the file system incrementally formats additional portions of the added allocated space and satisfies subsequent file I/O requests from the added portions.

Dense file reservation in thinly provisioned file system

Described are methods, systems, and apparatus, including computer program products for de-duplicating access control lists (ACLs). A first ACL associated with a first computer file is received. A first checksum based at least in part on the first ACL is calculated. One or more directory entries based on the first checksum are retrieved from a de-duplication directory, wherein each directory entry of the one or more directory entries comprises a reference to an ACL and a name comprising the first checksum. A directory entry of the one or more directory entries is identified that references a second ACL that specifies the same permissions as the first ACL. A reference to the second ACL of the directory entry is added to the first computer file.

De-duplication of access control lists

Techniques for shrinking a filesystem backed by a volume identify slices in the volume to be evacuated in order to reach a target size, identify a target endpoint in the volume, and evacuate identified slices to available locations prior to the target endpoint. The same data is typically not moved from slice to slice multiple times.

Efficiently shrinking a dynamically-sized volume

A method is used in managing data relocation in storage systems. A request is received to write to a slice of storage tier in a data storage system where the slice is being relocated. The relocation of the slice includes copying data of the slice to another slice in the data storage system. Location within the slice at which the request to write to the slice has been received is determined. Based on the determination, relocation of the slice of the storage tier is effected.

Managing data relocation in storage systems

A method, computer program product, and computing system for defining an initial root slice for a storage system. A first data slice is defined for the storage system. The location of the first data slice of the storage system is identified within the initial root slice. A request for a supplement data slice within the storage system is received. A determination is made as to if the supplement data slice can be added within the storage system without defining a supplemental root slice for a storage system.

System and method for storage management using root and data slices

A method, computer program product, and computer system for instantiating, by a computing device, a slice-object associated with a slice when the slice-object is accessed. The slice-object is released to a slice object cache when accessing is complete. It is determined whether the slice is accessed within a threshold period of time. If the slice is accessed within the threshold period of time, the slice-object is retrieved from the slice-object cache. If the slice is not accessed within the threshold period of time, memory used for the slice-object is released.

Sparse volume management cache mechanism system and method

A technique for verifying the consistency of slice allocation metadata includes accessing, from user space of an operating system running on the data storage apparatus, a set of drivers running in kernel space of the operating system to obtain slice allocation metadata from the set of drivers, and identifying discrepancies in slice allocation metadata returned from the set of drivers on a per-file-system basis.

Verifying the consistency of slice allocation metadata

Techniques are described for copying data using a throttling mechanism to achieve a desired time delay. A request is received to copy a data portion from a source location of a first physical device to a target location of a second physical device. A desired average delay time is determined in accordance with a plurality of values including a throttle value affecting a rate at which data is copied from the source location to the target location. The request is partitioned into subrequests. The data portion is partitioned into a subportions. Each of the subrequests copies one of the subportions. The subrequests are performed whereby a time delay is introduced between at least two of the plurality of subrequests and whereby an average time delay with respect to each pair of consecutively issued subrequests is the desired average time delay.

Throttling techniques for use with data relocation

Growing community of inventors

Shanghai, China

Qi Mao