Intelligent migration of a virtual storage unit to another data storage system

Patent metadata

Field	Value
Publication number	US-9477407-B1
Application number	US-201313930853-A
Country	US
Kind code	B1
Filing date	Jun 28, 2013
Priority date	Jun 28, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A virtual storage unit from one data storage system may be migrated to another data storage system. Utilization impacts on system resources by one or more virtual storage units on multiple data storage systems may be quantified, for each data storage system as a whole, or for a functional component of each data storage system. Based on these quantifications, multiple “what-if” scenarios may be considered to determine the consequences of migrating one or more virtual storage units from one of the data storage systems to another one of the data storage systems. If it is determined that a virtual storage unit is to be migrated, a live migration may be performed such that one or more hosts maintain access to the data of the virtual storage unit while the virtual storage unit is being migrated.

First claim

What is claimed is:

1. For a system comprising a first data storage system having a first plurality of virtual storage units, a second storage system having a second plurality of virtual storage units, and at least one host device connected to the first data storage system and the second data storage system, a method comprising:
for at least a first virtual storage unit of the first plurality of virtual storage units, quantifying an impact on performance of the first data storage system by the at least first virtual storage unit, comprising:
for a first functional component of the first data storage system, determining a first component utilization score indicative of a utilization of the first functional component by the first virtual storage unit;
for a second functional component of the first data storage system, determining a second component utilization score indicative of a utilization of the second functional component by the first virtual storage unit; and
combining the first and second component utilization scores to produce a utilization score for the first virtual storage unit indicative of an impact on performance of the first data storage system by the first virtual storage unit;

determining whether to migrate data of the at least first virtual storage unit from the first data storage system to a second data storage system based at least in part on the quantified impact of the at least first virtual storage unit; and
performing a migration of the data of the first virtual storage unit from the first data storage system to the second data storage system, wherein, concurrently to performance of the migration, the at least one host device maintains access to data of the first virtual storage unit.

2. The method of claim 1 , wherein the at least one host device has at least a first host device port for communicating with at least the first data storage system, and the first data storage system comprises at least a first data storage system port to communicate with at least the first host device port, and wherein a first data structure associated with at least the first storage port includes an entry mapping at least the first host device port to at least the first virtual storage unit thereby enabling communication between at least the first host device port and the first virtual storage unit, and
wherein the second data storage system comprises at least a second data storage system port to communicate with at least the first host device port, and a second data structure is associated with at least the second storage port, wherein the method further comprises:
configuring the entry in the first data structure so that communication between the first virtual storage unit and at least the first host device port is disabled; and
configuring an entry of the second data structure to enable communication between at least the first host device port and the migrated first virtual storage unit.

3. The method of claim 2 , wherein the system comprises at least a first switch in a communication path between the first data storage system, the second data storage system and the at least first host device, the first switch comprising a plurality of host ports for communicating with a plurality of host device ports and a plurality of storage ports for communicating with a plurality of storage device ports of the first data storage system and the second data storage system, the method further comprising:
configuring the switch so that communications are enabled between each of the plurality of host ports and each of the plurality of storage ports, thereby enabling communications between each of the plurality host ports and each of the plurality of storage ports.

4. The method of claim 1 , wherein quantifying the impact on performance comprises, for each of the first plurality of virtual storage units, quantifying the impact on performance of the data storage system by the virtual storage unit, and
wherein determining whether to migrate comprises selecting the at least first virtual storage unit from among the first plurality of virtual storage units for which to migrate the data to the second data storage system based at least in part on the quantified impacts.

5. The method of claim 1 , wherein the second data storage system has at least a second virtual storage unit, the method further comprising acts of:
for at least the second virtual storage unit, quantifying an impact on performance of the second data storage system by the at least second virtual storage unit, and
wherein determining whether to migrate comprises determining whether to migrate data of the at least first virtual storage unit from the first data storage system to the second data storage system based at least in part on the quantified impact of the at least second virtual storage unit.

6. The method of claim 1 , wherein the act of quantifying a performance of the first virtual storage unit comprises quantifying a performance of the first virtual storage unit during a plurality of temporal intervals over a temporal period to produce interval performance values, and
wherein the act of performing a migration comprises performing the migration during a particular temporal interval based at least in part on the interval performance values.

7. The method of claim 1 , wherein the first virtual storage unit has a unique identifier, and wherein performing the migration comprises:
creating a second virtual storage unit on the second data storage system;
assigning a same unique identifier to the second virtual storage unit, enabling the at least one host device to communicate concurrently with the first virtual storage unit and the second virtual storage unit;
placing the second virtual storage unit into a stalled-active mode in which responses to I/O operation requests received from a host system are delayed for up to a particular amount of time;
changing a mode of the first virtual storage unit from active mode, in which the first virtual storage unit is able to perform I/O operations, to passive mode in which the first virtual storage unit is not able to perform I/O operations;
changing a mode of the second virtual storage unit from the stalled active mode to an active mode in which the second virtual storage unit is able to perform I/O operations; and copying the data from the first virtual storage unit to the second virtual storage unit.

8. The method of claim 1 , wherein quantifying the impact of at least the first virtual storage unit comprises:
for at least one of the first and second functional components, for a plurality of types of storage I/O operations, counting a number of occurrences of the storage I/O operation type over a period of time to produce an I/O operation type count value for the at least first virtual storage unit for the at least one functional component; and
combining the I/O operation type count values.

9. For a computer system comprising a first data storage system having a first plurality of virtual storage units, a second storage system having a second plurality of virtual storage units, and at least one host device connected to the first data storage system and the second data storage system, a system comprising:
first logic to quantify, for at least a first virtual storage unit of the first plurality of virtual storage units, an impact on performance of the first data storage system by the at least first virtual storage unit, the first logic comprising:
logic to determine, for a first functional component of the first data storage system, a first component utilization score indicative of a utilization of the first functional component by the first virtual storage unit;
logic to determine, for a second functional component of the firs

Assignees

• Emc Corp
• Emc Ip Holding Co Llc

Inventors

• Marshak Marik
• Aharoni Dan
• Sahin Adnan
• Don Arieh
• Veprinsky Alexandr
• Natanzon Assaf

Classifications

• G06F3/0647

  Migration mechanisms · CPC title

• G06F12/08

  in hierarchically structured memory systems, e.g. virtual memory systems · CPC title

• G06F3/061 Primary

  Improving I/O performance · CPC title

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F12/0862

  with prefetch · CPC title