Emc IP Holding Company LLC

Xianlong Liu

Ruiling Dou

Changyong Yu

Alexander S Mathews

Liang Huang

Jianhua Shao

Ruipeng Yang

Chang Yong Yu

Sicong Yao

Philippe Armangau

Jean-Pierre Bono

Walter Forrester

Ahsan Rashid

Qi Mao

Banghui Luo

Xiaoliang Zhao

Gyanesh Kumar Choudhary

Yuetao Jiang

William C Davenport

Jun Hui Liu

Feng Zhang

Ye Zhang

Chao Zheng

Yingchao Zhou

Jing Chen

Yunfei Chen

Henry Hao Fang

Piers Yu

Techniques are directed to storage system management within a storage system. Such storage system management involves task scheduling. Along these lines, a group of tasks for execution may be selected based on task type use levels and priority levels. Accordingly, there may be more reasonable allocation of resources thus increasing the utilization of IO bandwidth.

Task scheduling based on task type use levels and priority levels

A storage management technique involves: determining a spare degree of physical storage space of a file system and access characteristics of the file system; determining, using a provision operation classification model and based on the spare degree and the access characteristics, a target storage provision operation to be performed for the file system from multiple storage provision operations, wherein the multiple storage provision operations include at least a storage space expansion operation and a storage space reclamation operation, and the provision operation classification model characterizes an association relationship between different spare degrees and different access characteristics of the file system and the multiple storage provision operations; and performing the determined target storage provision operation for the file system. Accordingly, a better balance is achieved between storage efficiency and I/O performance.

Performing storage provision operations on a file system

A technique for managing storage space includes establishing an MSR (minimum space reservation) of a thin file system built upon a storage pool. In response to a set of storage requests to the file system to store new data, the method further includes obtaining an additional space guarantee from the storage pool. After deleting data from the file system such that the size of the file system falls below the MSR, the technique further includes performing a space reclaim operation, the space reclaim operation (i) compacting the file system to a size less than the MSR, (ii) canceling the additional space guarantee such that the storage pool no longer guarantees the additional space for the file system, and (iii) continuing to reserve the full MSR of the file system, even though the size of the file system is smaller than the MSR.

Enforcing minimum space guarantees in thinly-provisioned file systems

Techniques for storage management involve: if it is determined that a source storage slice of a file system is to be recycled, identifying, from the source storage slice including a plurality of storage blocks, an orphan storage block that is inaccessible by a client of the file system; replicating data of the orphan storage block to a target storage block, the target storage block being located in a target storage slice within a predetermined isolation area of the file system; and generating second metadata of the target storage block based at least on first metadata of the orphan storage block, the second metadata including at least an identification of the orphan storage block. Therefore, the management performance can be improved, and the storage costs can be reduced.

Method, electronic device and computer program product for restoring orphan block via replication

Techniques for managing disks involve: determining a current usage parameter associated with each of a plurality of disk sets, the current usage parameter indicating usage associated with a capability of each of the plurality of disk sets, and the capability comprising at least one of the following: a number of permitted accesses per time unit and a number of permitted writes per time unit; imbalance degree associated with the plurality of disk sets, the first imbalance degree indicating a difference in the current usage parameters of the plurality of disk sets; and causing data in at least one disk slice of a first disk set to be moved to a second disk set of the plurality of disk sets, so as to lower down the first imbalance degree. In this way, a better balance can be achieved among performances of respective disks after adjustment.

Method, device and computer program product for managing disks

Techniques for managing disks involve determining, based on a parameter related to a capability of a plurality of disks, a reference capability parameter for each of the plurality of disks. In addition, the techniques involve determining a used capability parameter for each of the plurality of disks. Moreover, the techniques involve determining from the plurality of disks a first disk to be adjusted, a used capability parameter of the first disk exceeds a reference capability parameter of the first disk. The techniques further involve causing data of at least one disk slice in the first disk to be moved to a second disk of the plurality of disks, such that a difference between the used capability parameter of the first disk and reference capability parameter of the first disk is below a predetermined threshold. Accordingly, a balanced operation among respective storage disks can be achieved.

Method, electronic device and computer program product for managing disks

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

A data storage system manages use of a pool of secondary storage by internal file systems hosting logical data storage objects accessed by clients. A choose-and-mark-slices operation scans the file system to identify a subset of the slices as evacuatable slices to be de-provisioned and returned to the pool, the subset having a size exceeding a per-iteration limit observed by a separate evacuate-slices operation. The subset is recorded in an in-memory structure. Each iteration of the evacuate-slices operation (1) examines the in-memory structure to select slices for evacuation, no more than the per-iteration limit being selected, (2) moves data from the selected slices to the remaining slices of the set, and (3) subsequently (i) updates metadata of the file system to reflect the moving of the data and (ii) de-provisions the selected slices from the file-system to return them to the pool for subsequent re-provisioning.

Data storage system using in-memory structure for reclaiming space from internal file system to pool storage

A method includes (a) while processing data storage requests from users directed to filesystems of a plurality of filesystems served from a data storage system, receiving a request to execute a filesystem reorganization task on a filesystem of the plurality of filesystems, (b) in response to receiving the request, checking whether the filesystem reorganization task has both a global reorganization token and a filesystem-specific reorganization token, the filesystem-specific reorganization token being specific to the filesystem on which the filesystem reorganization task has been requested to execute, and (c) in response to determining that the filesystem reorganization task does have both the global reorganization token and the filesystem-specific reorganization token, executing the filesystem reorganization task to move a data block from one location within the filesystem to another location within the filesystem. Other embodiments are directed to corresponding apparatuses, computer program products, and systems for performing similar methods.

Techniques for efficiently performing filesystem reorganization tasks for different filesystems

A technique for performing storage tiering accesses allocation metadata in a data storage system and applies that allocation metadata when relocating data from a selected extent to a target extent. The selected extent includes a range of contiguous blocks. The allocation metadata may designate each of these blocks as either allocated or free. When relocating data from the selected extent to the target extent, the technique copies data of the selected extent on a per-block basis, checking whether that block is allocated or free before copying it to the target extent.

Mitigating flash wear when performing storage tiering

Techniques for improving storage efficiency of a data storage system are provided. The techniques include (a) performing a testing operation to evaluate whether a test condition is satisfied for a filesystem having a plurality of subspaces, each subspace being provisioned with a respective amount of storage, each subspace of the filesystem being dedicated to storing different respective types of filesystem content, wherein the test condition indicates that a first subspace has available space in excess of a threshold percentage, (b) in response to determining that the test condition is satisfied for the filesystem, performing a reduction operation on the first subspace to remove a portion of storage provisioned to that subspace while retaining the removed portion for use by the filesystem, and (c) upon a second subspace reaching a fullness threshold, provisioning the removed portion to the second subspace and storing content of the respective type of the second subspace thereon.

Techniques for rebalancing storage between subspaces

A data storage system manages a pool of secondary storage by internal file systems hosting logical data storage objects accessed by clients, the pool organized into fixed-size, dynamically provisioned slices. A first choose-and-mark-slices operation scans a set of slices to identify a first subset as evacuatable, and records them as a recorded subset in an in-memory structure. Iterations of an evacuate-slices operation (1) select slices from among the recorded subset, observing a per-iteration limit, (2) move data from the selected slices to remaining slices of the set, and (3) subsequently (i) updates file system metadata to reflect the data movement and (ii) de-provisions the selected slices and returns them to the pool. Between iterations, a change in the composition of evacuatable slices is detected, and a second choose-and-mark-slices operation re-scans the slices and records a second subset as the recorded subset for a subsequent iteration of the evacuate-slices operation.

Data storage system dynamically re-marking slices for reclamation from internal file system to pool storage

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.

Growing community of inventors

Shanghai, China

Xianlong Liu