Host processing of I/O operations

Patent metadata

Field	Value
Publication number	US-10698613-B1
Application number	US-201916389563-A
Country	US
Kind code	B1
Filing date	Apr 19, 2019
Priority date	Apr 19, 2019
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A host system performs I/O processing functions traditionally performed on storage systems. Metadata about data stored on the storage system may be stored on the host system, including metadata about the data stored in a cache of the storage system. The SSI may be configured to determine whether an I/O operation is a read or write operation. If the I/O operation is a read operation, the SSI may determine from metadata stored thereon whether the data to be read is in cache. If the data is in cache, the SSI may read the data directly from cache over the internal fabric without use of CPU resources of a director, and, in some embodiments, without use of a director at all. If the data is not in cache, the SSI may read the data directly from the physical storage device over the internal fabric without use of a director.

First claim

What is claimed is:

1. For a system including a data storage system having a plurality of physical storage devices and one or more directors that process input/output (I/O) operations involving the data stored on the plurality of physical storage devices, each of the one or more directors including one or more processing cores, and a host system having one or more applications running thereon, the execution of each of the one or more application resulting in I/O operations involving data stored on a storage system, a method comprising:
receiving a read request originating from a first of the one or more applications, the read request specifying a read operation for a portion of data stored on a first of the plurality of physical devices;
determining whether the portion of data resides in a cache of the data storage system; and
if it is determined that the portion does not reside in the cache, the host system accessing the portion of data from the first physical storage device independently of the one or more directors.

2. The method of claim 1 , further comprising:
if it is determined that the portion does reside in the cache, the host system accessing the portion of data from the cache independently of any of the processing cores of the one or more directors.

3. The method of claim 2 , wherein the storage system includes an internal switching fabric for communication between data storage resources internal to the data storage system, and
wherein the host system accesses the cache along a communication path that includes the internal switching fabric and that does not include any of the processing cores of the one or more directors.

4. The method of claim 1 , wherein the storage system includes an internal switching fabric for communication between data storage resources internal to the data storage system, and
wherein the host system accesses the data portion on the first physical storage device along a communication path that includes the internal switching fabric and that does not include any of the one or more directors.

5. The method of claim 4 , wherein the host system encapsulates communications sent over the internal switching fabric concerning the data portion as non-volatile memory express over fabric (NVMf) command capsules, and
wherein storage system includes an interface between the internal switching fabric and the first physical storage device along the communication path, the interface de-capsulating communications received from the host system over the internal switching fabric.

6. The method of claim 1 , wherein whether the portion of data resides in the cache is determined on the host system independently of the storage system.

7. The method of claim 6 , wherein metadata about the cache resides on the host system, and
wherein whether the portion of data resides in the cache is determined by accessing the metadata on the host system.

8. A host system having one or more applications running thereon, the execution of each of the one or more application resulting in input/output (I/O) operations involving data stored on a storage system having a plurality of physical storage devices and one or more directors that process I/O operations involving the data stored on the plurality of physical storage devices, each of the one or more directors including one or more processing cores, the host system comprising:
one or more processors;
first logic that receives a read request originating from a first of the one or more applications, the read request specifying a read operation for a portion of data stored on a first of the plurality of physical devices;
second logic that determines whether the portion of data resides in a cache of the data storage system; and
third logic that controls accessing the portion of data from the first physical storage device independently of the one or more directors if it is determined that the portion does not reside in the cache.

9. The host system of claim 8 , wherein the host system includes logic that, if the second logic determines that the portion does reside in the cache, controls accessing the portion of data from the cache independently of any of the processing cores of the one or more directors.

10. The host system of claim 9 , wherein the storage system includes an internal switching fabric for communication between data storage resources internal to the data storage system, and
wherein the host system includes logic to control accessing the cache along a communication path that includes the internal switching fabric and that does not include any of the processing cores of the one or more directors.

11. The host system of claim 8 , wherein the storage system includes an internal switching fabric for communication between data storage resources internal to the data storage system, and
wherein the host system includes logic that accesses the data portion on the first physical storage device along a communication path that includes the internal switching fabric and that does not include any of the one or more directors.

12. The host system of claim 11 , wherein the host system includes logic that encapsulates communications sent over the internal switching fabric concerning the data portion as non-volatile memory express over fabric (NVMf) command capsules, and
wherein storage system includes an interface between the internal switching fabric and the first physical storage device along the communication path, the interface de-capsulating communications received from the host system over the internal switching fabric.

13. The host system of claim 8 , wherein the second logic determines whether the portion of data resides in the cache independently of the storage system.

14. The host system of claim 13 , wherein metadata about the cache resides on the host system, and
wherein the second logic determines whether the portion of data resides in the cache by accessing the metadata on the host system.

15. For a system including a data storage system having a plurality of physical storage devices and one or more directors that process input/output (I/O) operations involving the data stored on the plurality of physical storage devices, each of the one or more directors including one or more processing cores, and a host system having one or more applications running thereon, the execution of each of the one or more application resulting in I/O operations involving data stored on a storage system, one or more non-transitory computer-readable media, the computer-readable media having software stored thereon comprising:
executable code that receives a read request originating from a first of the one or more applications, the read request specifying a read operation for a portion of data stored on a first of the plurality of physical devices;
executable code that determines whether the portion of data resides in a cache of the data storage system; and
executable code that accesses the portion of data from the first physical storage device independently of the one or more directors if it is determined that the portion does not reside in the cache, the host system.

16. The one or more non-transitory computer-readable media of claim 15 , the software further comprising:
executable code that controls the host system to access the portion of data from the cache independently of any of the processing cores of the one or more directors if it is determined that the portion does reside in the cache.

17. The one or more non-transitory computer-readable media of claim 16 , wherein the storage system includes an internal switching fab

Assignees

• Emc Ip Holding Co Llc

Inventors

• Wigmore Ian
• Tringale Alesia A
• Duquette Jason J

Classifications

• G06F2212/462

  Track or segment · CPC title

• G06F2212/313

  In storage device · CPC title

• G06F2212/262

  configured as RAID · CPC title

• G06F2212/261

  Storage comprising a plurality of storage devices · CPC title

• G06F2212/154

  Networked environment · CPC title