Method, device and computer program product for expanding storage space

Patent metadata

Field	Value
Publication number	US-11099761-B2
Application number	US-201916249364-A
Country	US
Kind code	B2
Filing date	Jan 16, 2019
Priority date	Jan 18, 2018
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

Techniques expand storage space. Such techniques can create a storage stripe group during a shuffling operation after a storage device being added, without waiting for full completion of the shuffling operation. Such techniques can effectively reduce the waiting time for creating the storage stripe group. Besides, such techniques can support partial mapping of the storage stripe group, such that the storage resources mapped to the storage stripe group can be rapidly utilized.

First claim

We claim:

1. A method of managing a storage system, the storage system including a plurality of storage devices, the method comprising:
receiving a creating request for creating a group of storage stripes of the storage system, the creating request indicating a width of the group of storage stripes to be created;
in response to adding a storage device to the storage system, initiating redistribution of data across the plurality of storage devices and the added storage device, the initiating redistribution of data comprising:
transferring all data from a first plurality of storage extents on the plurality of storage devices to a second plurality of storage extents on the added storage device, respectively, the first plurality of storage extents having all of its data transferred being referred to herein as a plurality of free storage extents; and

performing, before the redistribution of data is completed, acts comprising:
initiating creation of the group of storage stripes, the initiating creation comprising:
obtaining a first plurality of target storage extents satisfying the width from at least the plurality of free storage extents on the plurality of storage devices;
selecting, from the first plurality of target storage extents, a first group of free storage extents on at least different ones of the plurality of storage devices, respectively, the first group of free storage extents having a first number of free storage extents corresponding to the width of the group of storage stripes; and
performing partial mapping of free storage extents to the group of storage stripes, the partial mapping comprising:
mapping a physical address of the first group of free storage extents to a logical address of a first storage stripe of the group of storage stripes; and
mapping the logical address of the first storage stripe to a logical address of the group of storage stripes, a size of accessible storage space in the group of storage stripes corresponding to a size of storage space in the first group of free storage extents; and

accessing the storage space in the first group of free storage extents mapped to the first storage stripe of the group of storage stripes.

2. The method of claim 1 , wherein the creating request further indicates a total accessible storage space in the group of storage stripes to be created, and wherein the initiating creation of the group of storage stripes further comprises:
determining that the size of accessible storage space is less than the total accessible storage space indicated in the creating request; and
in response to determining that the size of accessible storage space is less than the total accessible storage space indicated in the creating request, selecting, from the first plurality of target storage extents, at least a second group of free storage extents on at least different ones of the plurality of storage devices, respectively, the second group of free storage extents having a second number of free storage extents corresponding to the width of the group of storage stripes.

3. The method of claim 2 , wherein the performing partial mapping further comprises:
mapping a physical address of the second group of free storage extents to a logical address of a second storage stripe of the group of storage stripes;
mapping the logical address of the second storage stripe to the logical address of the group of storage stripes; and
updating the size of accessible storage space in the group of storage stripes to a total combined size of (i) the size of storage space in the first group of free storage extents mapped to the first storage stripe of the group of storage stripes and (ii) a size of storage space in the second group of free storage extents mapped to the second storage stripe of the group of storage stripes.

4. The method of claim 3 , further comprising:
marking the group of storage stripes as having storage space that is fully accessible.

5. The method of claim 1 , further comprising:
obtaining a second plurality of target storage extents from at least the plurality of free storage extents on the plurality of storage devices;
in response to the second plurality of target storage extents failing to satisfy the width, waiting for one or more additional storage extents to be released during the redistribution of data; and
updating the second plurality of target storage extents using the one or more additional storage extents released by the redistribution of data.

6. The method of claim 1 , wherein the initiating creation of the group of storage stripes further comprises:
creating a logical unit related to the group of storage stripes; and
outputting information associated with the logical unit for accessing the accessible storage space in the group of storage stripes.

7. The method of claim 1 , further comprising:
transmitting, to a volatile drive memory, information indicating the accessible storage space in the group of storage stripes.

8. A device for managing a storage system, comprising:
a plurality of storage devices;
at least one processing unit; and
at least one memory coupled to the at least one processing unit and stored with instructions, the instructions, when executed by the at least one processing unit, performing acts comprising:
receiving a creating request for creating a group of storage stripes of the storage system, the creating request indicating a width of the group of storage stripes to be created
in response to adding a storage device to the storage system, initiating redistribution of data across the plurality of storage devices and the added storage device, the initiating redistribution of data comprising:
transferring all data from a first plurality of storage extents on the plurality of storage devices to a second plurality of storage extents on the added storage device, respectively, the first plurality of storage extents having all of its data transferred being referred to herein as a plurality of free storage extents; and

performing, before the redistribution of data is completed, acts comprising:
initiating creation of the group of storage stripes, the initiating creation comprising:
obtaining a first plurality of target storage extents satisfying the width from at least the plurality of free storage extents on the plurality of storage devices;
selecting, from the first plurality of target storage extents, a first group of free storage extents on at least different ones of the plurality of storage devices, respectively, the first group of free storage extents having a first number of free storage extents corresponding to the width of the group of storage stripes; and
performing partial mapping of free storage extents to the group of storage stripes, the partial mapping comprising:
 mapping a physical address of the first group of free storage extents to a logical address of a first storage stripe of the group of storage stripes; and
 mapping the logical address of the first storage stripe to a logical address of the group of storage stripes, a size of accessible storage space in the group of storage stripes corresponding to a size of storage space in the first group of free storage extents; and
accessing the storage space in the first group of free storage extents mapped to the first storage stripe of the group of storage stripes.

9. The device of claim 8 , wherein the creating request further indicates a total accessible storage space in the group of storage stripes to be created, and wherein the initiating creation of the group of storage stripes further comprises:
determining that the size of accessible storage space is less than the total accessible storage space indicated in the creating request; and
in response to

Assignees

• Emc Ip Holding Co Llc

Inventors

• Liu Yousheng
• Kang Jianbin
• Xu Xinlei
• Yang Lifeng
• Gao Jian

Classifications

• G06F3/0611

  in relation to response time · CPC title

• G06F3/064

  Management of blocks · CPC title

• G06F11/1076 Primary

  Parity data used in redundant arrays of independent storages, e.g. in RAID systems · CPC title

• G06F3/0604

  Improving or facilitating administration, e.g. storage management · CPC title

• G06F3/0647 Primary

  Migration mechanisms · CPC title