US 11,079,961 B1Granted

Storage system with write-via-hash functionality for synchronous replication of logical storage volumes

AssigneeEMC IP Holding Company LLC

InventorsDavid Meiri, Xiangping Chen

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Abstract

An apparatus includes a processing device comprising a processor coupled to a memory. The processing device is configured, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems, to receive a synchronous write request comprising a data page to be written to the logical storage volume, to determine a content-based signature for the data page, and to send the content-based signature from the first storage system to the second storage system. Responsive to receipt in the first storage system of an indication from the second storage system that the data page having the content-based signature is not already present in the second storage system, the processing device is further configured to send the data page from the first storage system to the second storage system. The processing device in some embodiments implements a distributed storage controller of a content addressable storage system.

Claims20

Dependent claims

An apparatus comprising:

at least one processing device comprising a processor coupled to a memory;
said at least one processing device being configured, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems:
to receive a synchronous write request comprising a data page to be written to the logical storage volume;
to determine a content-based signature for the data page;
to send the content-based signature from the first storage system to the second storage system;
and
responsive to receipt in the first storage system of an indication from the second storage system that the data page having the content-based signature is not already present in the second storage system, to send the data page from the first storage system to the second storage system;
wherein the synchronous replication comprises a plurality of synchronous replication sessions each involving one or more logical storage volumes;
and
wherein each of one or more of the synchronous replication sessions has a deduplication threshold and is configured:
to initially process a designated amount of its synchronous write requests by first sending content-based signatures for respective data pages of the synchronous write requests to the second storage system instead of first sending the data pages, in order to determine if the data pages already exist in the second storage system so as to thereby potentially avoid sending the data pages;
to determine an initial value of a deduplication ratio based at least in part on results of the initial processing;
and
for each of a plurality of additional synchronous write requests:
responsive to a current value of the deduplication ratio being above the deduplication threshold, first sending a content-based signature for a data page of the synchronous write request to the second storage system instead of first sending the data page, in order to determine if the data page already exists in the second storage system so as to thereby potentially avoid sending the data page;
and
responsive to a current value of the deduplication ratio not being above the deduplication threshold, first sending the data page.

14 more elements

An apparatus comprising:

at least one processing device comprising a processor coupled to a memory;
said at least one processing device being configured, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems:
to receive a synchronous write request comprising a data page to be written to the logical storage volume;
to determine a content-based signature for the data page;
to send the content-based signature from the first storage system to the second storage system;
and
responsive to receipt in the first storage system of an indication from the second storage system that the data page having the content-based signature is not already present in the second storage system, to send the data page from the first storage system to the second storage system;
wherein the synchronous replication comprises a plurality of synchronous replication sessions each involving one or more logical storage volumes;
wherein the first storage system comprises a distributed storage system having a plurality of storage nodes, each of at least a subset of the storage nodes comprising a set of processing modules configured to communicate with corresponding sets of processing modules on other ones of the storage nodes, a given such set of processing modules comprising at least a routing module, a control module and a data module, the sets of processing modules of the storage nodes collectively comprising at least a portion of a distributed storage controller of the distributed storage system;
and
wherein said at least one processing device is further configured:
to determine a number of parallel synchronous write requests that can be collectively supported by the routing modules;
to determine a replication budget for each of the control modules as a function of the number of parallel synchronous write requests;
to allocate portions of the replication budget across the synchronous replication sessions in accordance with respective priority levels assigned thereto;
and
to assign synchronous write requests to respective ones of the synchronous replication sessions in accordance with their respective allocated portions of the replication budget.

13 more elements

A method comprising:

in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems:
receiving a synchronous write request comprising a data page to be written to the logical storage volume;
determining a content-based signature for the data page;
sending the content-based signature from the first storage system to the second storage system;
and
responsive to receipt in the first storage system of an indication from the second storage system that the data page having the content-based signature is not already present in the second storage system, sending the data page from the first storage system to the second storage system;
wherein the synchronous replication comprises a plurality of synchronous replication sessions each involving one or more logical storage volumes;
wherein each of one or more of the synchronous replication sessions has a deduplication threshold and is configured:
to initially process a designated amount of its synchronous write requests by first sending content-based signatures for respective data pages of the synchronous write requests to the second storage system instead of first sending the data pages, in order to determine if the data pages already exist in the second storage system so as to thereby potentially avoid sending the data pages;
to determine an initial value of a deduplication ratio based at least in part on results of the initial processing;
and
for each of a plurality of additional synchronous write requests:
responsive to a current value of the deduplication ratio being above the deduplication threshold, first sending a content-based signature for a data page of the synchronous write request to the second storage system instead of first sending the data page, in order to determine if the data page already exists in the second storage system so as to thereby potentially avoid sending the data page;
and
responsive to a current value of the deduplication ratio not being above the deduplication threshold, first sending the data page;
and
wherein the method is implemented by at least one processing device comprising a processor coupled to a memory.

14 more elements

A computer program product comprising a non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes said at least one processing device, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems:

to receive a synchronous write request comprising a data page to be written to the logical storage volume;
to determine a content-based signature for the data page;
to send the content-based signature from the first storage system to the second storage system;
and
responsive to receipt in the first storage system of an indication from the second storage system that the data page having the content-based signature is not already present in the second storage system, to send the data page from the first storage system to the second storage system;
wherein the synchronous replication comprises a plurality of synchronous replication sessions each involving one or more logical storage volumes;
and
wherein each of one or more of the synchronous replication sessions has a deduplication threshold and is configured:
to initially process a designated amount of its synchronous write requests by first sending content-based signatures for respective data pages of the synchronous write requests to the second storage system instead of first sending the data pages, in order to determine if the data pages already exist in the second storage system so as to thereby potentially avoid sending the data pages;
to determine an initial value of a deduplication ratio based at least in part on results of the initial processing;
and
for each of a plurality of additional synchronous write requests:
responsive to a current value of the deduplication ratio being above the deduplication threshold, first sending a content-based signature for a data page of the synchronous write request to the second storage system instead of first sending the data page, in order to determine if the data page already exists in the second storage system so as to thereby potentially avoid sending the data page;
and
responsive to a current value of the deduplication ratio not being above the deduplication threshold, first sending the data page.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/779,828Filed 3 Feb 2020
Published: US 2021/0240349 A15 Aug 2021
Granted: 3 Aug 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

G06F 3/065
Horizontal data movement in storage systems, i.e. moving data in between storage devices or systems: replication mechanisms
G06F 3/0608
Specifically adapted to achieve a particular effect: saving storage space on storage systems
G06F 3/061
Specifically adapted to achieve a particular effect: improving I/O performance
G06F 3/0613
Improving I/O performance: in relation to throughput