Using Fcip Tape Acceleration

Chapter 4 FCIP over IP/MPLS Core

Using FCIP Tape Acceleration

Write Acceleration

Write Acceleration is a configurable feature introduced in SAN-OS 1.3 that enhances FCIP SAN extension with the IP Storage Services Module. Write Acceleration is a SCSI protocol spoofing mechanism that improves application performance by reducing the overall service time for SCSI write input/output (I/O) operations and replicated write I/Os over distance. Most SCSI Fibre Channel Protocol (FCP) write I/O exchanges consist of two or more round trips between the host initiator and the target array or tape. Write Acceleration reduces the number of FCIP WAN round trips per SCSI FCP write I/O to one.

Write Acceleration is helpful in the following FCIP SAN extension scenarios:

•Distance and latency between data centers inhibits synchronous replication performance and impacts overall application performance.

•Upper layer protocol chattiness inhibits replication throughput, and the underlying FCIP and IP transport is not optimally utilized.

•Distance and latency severely reduces tape write performance during remote tape backup because tapes typically allow only a single outstanding I/O. Write Acceleration can effectively double the supported distance or double the transfer rate in this scenario.

•Shared data clusters are stretched between data centers and one host must write to a remote storage array.

The performance improvement from Write Acceleration typically approaches 2 to 1, but depends upon the specific situation.

Write Acceleration increases replication or write I/O throughput and reduces I/O response time in most situations, particularly as the FCIP Round Trip Time (RTT) increases. Each FCIP link can be filled with a number of concurrent or outstanding I/Os. These I/Os can originate from a single replication source or a number of replication sources. The FCIP link is filled when the number of outstanding I/Os reaches a certain ceiling. The ceiling is mostly determined by the RTT, write size, and available FCIP bandwidth. If the maximum number of outstanding I/Os aggregated across all replication sessions (unidirectional) is less than this ceiling, then the FCIP link is underutilized and thus benefits from Write Acceleration.

FCIP Tape Acceleration is a new feature introduced in SAN-OS 2.0 to improve remote tape backup performance by minimizing the effect of network latency or distance on remote tape applications. With FCIP Tape Acceleration, the local Cisco MDS 9000 IPS or MPS module proxies as a tape library. The remote MDS 9000, where the tape library is located, proxies as a backup server.

Similar to Write Acceleration, the MDS 9000 recognizes and proxies elements of the upper level SCSI protocol to minimize the number of end-to-end round trips required to transfer a unit of data and to optimally use the available network bandwidth. FCIP Write Acceleration achieves this by proxying the SCSI Transfer Ready and Status responses (in contrast, Write Acceleration proxies the Transfer Ready only). Write Filemarks and other non-write operations are not proxied and are passed directly to the remote tape library. The Write Filemarks operation corresponds to a checkpoint within the tape backup application. This is typically a tunable parameter but may default to 100 or 200 records depending upon the tape backup product.

Data Center High Availability Clusters Design Guide

	OL-12518-01	4-7

OL-12518-01 specifications

Cisco Systems OL-12518-01, also known as the Cisco Management Services for Wireless LAN Controller, is a key component for businesses seeking to enhance their wireless networking capabilities. This product offers a comprehensive management solution designed to ensure high performance and security of wireless networks.

One of the main features of OL-12518-01 is its centralized management interface, which simplifies the deployment and operation of multiple access points across an organization. This centralized approach allows network administrators to manage all wireless devices from a single pane of glass, significantly improving operational efficiency and reducing the potential for human error.

The product is built upon various robust technologies that enhance its performance. It includes advanced features like Quality of Service (QoS) support, which prioritizes bandwidth for critical applications. This ensures that mission-critical operations run smoothly, even in environments with high user density. Furthermore, the Wireless LAN Controller supports a variety of security protocols, including WPA3, ensuring that user data and wireless networks are protected against unauthorized access.

A significant characteristic of OL-12518-01 is its scalability. As businesses grow, their network requirements can change dramatically. The Cisco Management Services solution is designed to scale easily alongside the organization’s needs, allowing for the addition of more access points and the integration of advanced features seamlessly. This adaptability makes it suitable for both small businesses and large enterprises, ensuring consistent wireless connectivity across diverse spaces.

Moreover, OL-12518-01 features robust analytics and reporting capabilities. It provides valuable insights into network performance and user behavior, enabling administrators to make informed decisions about resource allocation and troubleshooting. With real-time monitoring tools, IT staff can quickly identify and resolve issues, minimizing downtime and enhancing overall user experience.

In summary, Cisco Systems OL-12518-01 is a powerful wireless LAN management solution that combines centralized management, advanced security features, scalability, and comprehensive analytics. These characteristics make it an ideal choice for organizations aiming to optimize their wireless networking performance while ensuring security and reliability in their operations. By investing in OL-12518-01, businesses can achieve a robust wireless infrastructure that meets their current and future needs.