Texas Memory Systems RamSan-500 Connecting the Fibre Channel Ports, Host Bus Adapter, PCI Bus

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connections requires one of the following solutions: multi-pathing software to a single LUN, using software to stripe across multiple LUNs, accessing multiple LUNs on the RamSan-500 concurrently, or connecting multiple servers to the system.

3.1.2 Host Bus Adapter

You can modify some HBA settings to increase performance. For information specific to your HBA, consult the HBA documentation. Note that many settings are intended to increase the performance of slow storage devices and will not be applicable to RamSans. It is always advisable to check the frame size. The amount of overhead for each Fibre Channel frame is fixed, so larger frames have lower overhead. Set the frame size to the maximum setting, generally 2048 bytes.

3.1.3 PCI Bus

High bandwidth HBA traffic can quickly inundate slower PCI buses. Once a PCI bus reaches its limit, you can do very little to improve performance. Many servers, however, provide different PCI buses with different speeds, and placing the HBA on a different PCI bus can improve performance. TMS recommends giving each 4-gigabit 2 port HBA at least an entire PCIX bus or a PCI Express (PCIe) slot.

3.1.4 CPU

At a certain point, CPU performance can limit data transfer rates. Determine whether the server’s CPU resources are the limiting factor in performance while benchmarking the RamSan-500 as a raw physical device. Otherwise, an improperly tuned file system or application can make the CPU appear to be the limiting factor when it is not. Perform raw device testing after setting up any multi-pathing.

There are a few ways to decrease CPU usage without increasing CPU resources. Certain data usage patterns can be very CPU intensive and fully utilize the CPU. These usually involve small transfer sizes. When possible, increasing the average transfer size decreases CPU usage and offers better performance. Another way to decrease CPU usage is by enabling interrupt coalescing. Interrupt coalescing is an HBA dependent feature that offers a method to trade latency for CPU usage. This feature delays calling the HBA transfer interrupt until several transfers are ready. In general, TMS does not recommend enabling Interrupt Coalescing, because most RamSan applications benefit from low latency. For more information, consult your HBA documentation.

3.2 Connecting the Fibre Channel Ports

Connect the Fibre Channel ports on the RamSan-500 to your server or to a Fibre Channel switch.

RamSan-500 User’s Manual

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Contents RamSan-500 User’s Manual Revision History Table of Contents Introduction PowerOverview System ComponentsSystem Management ReliabilityUnpacking Reviewing your shipmentSystem Overview System InspectionRamSan-500 Back Rack mountingInstalling a Host Bus Adaptor in the Host System ConnectionsFibre Channel Interface Host Bus Adapter Connecting the Fibre Channel PortsPCI Bus 4 CPUFibre Channel Port Locations Connecting to a NetworkConnecting Power to the System Power SwitchesAC Voltage Indicator Light Getting Started Turning on the SystemSystem Initialization Front Panel Display Basics Manual Shutdown Controlling System Power with the Front Panel DisplayFlash Modules Identify Module Module Network Configuration with the Front Panel Display Manual RestartAutomatic Shutdown Dhcp Ethernet IP address 192.000.000.000 Additional System Management Options Connecting using a Terminal ProgramConnecting using Snmp Connecting using TelnetConnecting using the Web Monitor Web Monitor BasicsAcquiring the System IP Address Accessing the Web MonitorWeb Monitor Information Date and time setup with the Web monitor Web Monitor Network Management Network Configuration with the Web MonitorDefault Accounts Changing PasswordsManaging security with the Web Monitor RamSan-500 User’s Manual Basic LUN Creation Adding UsersCreating a LUN RamSan-500 User’s Manual Adding an Access Policy to a LUN RamSan-500 User’s Manual Web Monitor Cache Configuration Configuring the RamSan-500 CacheViewing the Logs with the Web Monitor RamSan-500 User’s Manual Web Monitor System Report Web Monitor Patch Selection Upgrading the System with the Web MonitorIf the System has a Problem Contacting Texas Memory SystemsClearing the System Event Log RamSan-500 User’s Manual System Maintenance Power SuppliesContacting Texas Memory Systems Replace Failed Power Modules AS Soon AS Possible Flash Modules OFF Flash Module FailureWeb Monitor Flash Module Failure Detection Web Monitor RAID Degraded Detection RAID Failure Fans RamSan-500 User’s Manual Batteries