Cisco Technology, Inc.

Sanjaya Kumar

Samar Sharma

Dinesh Ganapathy Dutt

Thomas James Edsall

Umesh Mahajan

Roy D'Cruz

Srinivas Avasarala

Fabio Rodolfo Maino

Jeevan Madhu Kamisetty

Prashant Billore

Rajesh Bhandari

Jhaanaki M Krishnan

Rahul Chari

Silvano Gai

Varagur Chandrasekaran

Arindam Paul

Manas Barooah

John L Burnett

Giridhar Rajaram

Roy M D'CRUZ

A technique is provided for implementing online mirroring of a volume in a storage area network. A first instance of the volume is instantiated at a first port of the fiber channel fabric for enabling I/O operations to be performed at the volume. One or more mirroring procedures may be performed at the volume. In at least one implementation, the first port is able to perform first I/O operations at the volume concurrently while the mirroring procedures are being performed at the first volume. In one implementation, the mirroring procedures may be implemented at a fabric switch of the storage area network. Additionally, in at least one implementation, multiple hosts may be provided with concurrent access to the volume during the mirroring operations without serializing the access to the volume.

Mirroring mechanisms for storage area networks and network based virtualization

Methods and apparatus for performing SPAN for a virtual port are disclosed. Specifically, a frame is received from a first port. The frame or a copy thereof is transmitted to a second port, where the second port is identified in a header of the frame. At least one of the first port and the second port is a virtual port. The frame or a copy thereof is also transmitted to a third port, thereby enabling an analyzer coupled to the third port to analyze traffic received by the third port.

Virtual port based span

The disclosed embodiments support improvements in network performance in networks such as storage area networks. This is particularly important in networks such as those implementing virtualization. These improvements, therefore, support improved mechanisms for performing processing in network devices such as switches, routers, or hosts. These improvements include various different mechanisms which may be used separately or in combination with one another. These mechanisms include methods and apparatus for processing traffic in an arbitrated loop, performing striping to support fairness and/or loop tenancy, performing configuration of network devices such as switches to enable virtualization to be performed closest to the storage device (e.g., disk), ascertaining a CPU efficiency that quantifies the impact of virtualization on a processor, and configuring or accessing a striped volume to account for metadata stored in each storage partition.

Network based virtualization performance

Disclosed is a data recovery mechanism associated with a data writing process in a storage area network (SAN). In general, a data writing mechanism is provided so that a particular host can write data to a storage device in a particular SAN session. One specific example of a data writing mechanism is a data tapping mechanism that provides a copy of this data to an appliance. The data recovery mechanism allows the appliance to recover data from the particular target, for example, when the data was unsuccessfully mirrored to the appliance during the data tapping or when the appliance needs to obtain the data that was written prior to a data tapping procedure being initiated. In one embodiment, the data recovery mechanism is set up so that the appliance can recover data from the target by mimicking the particular host.

Apparatus and methods for an appliance to recover data from a storage device

Methods and apparatus provide formation and management of intelligent application clusters in a storage area network. Disk arbitration mechanisms ensure that a cluster is owned by a single member. In the event of a network partition, each cluster member involved arbitrates to gain ownership of a cluster. High availability mechanisms allow monitoring of system resources and effective failover capabilities.

High availability for intelligent applications in storage networks

Virtual port based SPAN

In one embodiment, a network device receives a port login directed to a target from a first host. The network device determines whether at least one other host is currently logged in to the target. The network device may then send a port login to the target corresponding to whether at least one other host is currently logged in to the target.

Fibre channel intelligent target management system

In one embodiment, a MUD logger receives a notification from another MUD logger maintaining another MUD log for a volume, the notification indicating one or more modifications to be made to a MUD log maintained by the MUD logger receiving the notification, wherein the MUD log includes information for one or more epochs, wherein the information for each of the epochs indicates a set of one or more regions of the volume that have been modified during the corresponding epoch. The MUD logger updates the MUD log associated with the volume, wherein updating the MUD log is performed in response to the notification.

Epoch-based MUD logging

A technique is provided for implementing online restriping of a volume in a storage area network. A first instance of the volume is instantiated at a first port of the fibre channel fabric for enabling I/O operations to be performed at the volume. While restriping operations are being performed at the volume, the first port is able to concurrently perform I/O operations at the volume.

Online restriping technique for distributed network based virtualization

Methods and apparatus are provided for determining traffic characteristics and statistics for storage area network flows. An intelligent line card associated with a fibre channel switch is used to snoop selected flows in a storage area network. Flows are characterized using information that may include initiator target pairs and initiator target logical unit number (LUN) groupings. Selected flows are configured for monitoring and information about the selected flows is maintained. Selected flow information can be analyzed at a line card associated with a fibre channel switch.

Determining traffic flow characteristics in a storage area network

Embodiments of the invention support improvements in network performance in networks such as storage area networks. This is particularly important in networks such as those implementing virtualization. These improvements, therefore, support improved mechanisms for performing processing in network devices such as switches, routers, or hosts. These improvements include various different mechanisms which may be used separately or in combination with one another. These mechanisms include methods and apparatus for processing traffic in an arbitrated loop, performing striping to support fairness and/or loop tenancy, performing configuration of network devices such as switches to enable virtualization to be performed closest to the storage device (e.g., disk), ascertaining a CPU efficiency that quantifies the impact of virtualization on a processor, and configuring or accessing a striped volume to account for metadata stored in each storage partition.

Methods and apparatus for improving network based virtualization performance

Methods and apparatus for performing MUD logging for a volume in a system implementing network-based virtualization are disclosed. This is accomplished by enabling two or more MUD loggers to separately maintain a MUD log for the volume. Through enabling the MUD loggers to communicate, the MUD loggers may update their respective MUD logs. Each MUD log includes information for one or more epochs, where the information for each of the epochs indicates a set of one or more regions that have been modified during the corresponding epoch.

Methods and apparatus for implementing storage virtualization on a network device of a storage area network are disclosed. A virtual enclosure is created that has one or more virtual enclosure ports and is adapted for representing one or more virtual storage units. Each of the virtual storage units represents one or more physical storage locations on one or more physical storage units of the storage area network. Each of the virtual enclosure ports of the virtual enclosure is associated with a port of a network device within the storage area network. An address or identifier is then assigned to each of the virtual enclosure ports.

Methods and apparatus for implementing virtualization of storage within a storage area network through a virtual enclosure

Disclosed is apparatus and methods for enabling an appliance to receive data being sent between any host of a host cluster to a specified storage device's logical unit (LUN) in a single stream or session. In one embodiment, a data virtual target is initially set up for a specified storage device LUN so that data written from a host to the specified storage device LUN is received by the DVT. An appliance then sends a session request to mirror data that is sent to the DVT (and specified storage device LUN) to a specified LUN of the appliance. The session request is not host specific. That is, data that is sent by any host to the DVT is mirrored to the same appliance LUN.

Growing community of inventors

Fremont, CA, United States of America

Sanjaya Kumar