- Creating an iSCSI service
Scope of document
This document provides guidelines and instructions for setting up the iSCSI network connectivity, as a preliminary task for setting up the InfiniBox services.
- InfiniBox Best Practices Guide for Setting Up the Network Connectivity
- Describes how to set up the physical network prior to setting up the services
- InfiniBox Best Practices Guide for Setting Up an iSCSI Service (this document)
- InfiniBox Best Practices Guide for Setting Up Fibre Channel
InfiniBox employs a true active-active-active I/O handling mechanism that ensures proper load balancing of all resources under all conditions, including failure scenarios. It is highly recommended to engage all three (3) nodes for all hosts. This ensures best performance, increases overall host reliability, and provides consistent performance during failure scenarios.
We recommend that you choose either Round Robin or Least Queue (or equivalent algorithms) as the multipath policy.
These multipath policies use all the paths connected to the storage, with slight changes on the path selection for each I/O operation.
- For Linux and UNIX hosts, the recommended multipath policy is Round Robin.
- For Windows hosts, the recommended multipath policy is Least Queue Depth (LQD).
- For vSphere hosts running version 6.5 or below, the recommended multipath policy is Round Robin with IOPS policy (iops policy set to 1).
- For vSphere hosts running version 6.7 or above, the recommended multipath policy is Round Robin with latency policy (policy set to latency).
Multipathing (Path Changing Frequency)
InfiniBox’s data distribution algorithm ensures utilization of all the drives all the time. To achieve best utilization of all nodes, multipath / OS drivers spread I/O across all the paths in a regular schedule. To yield best overall results, set the frequency for switching between paths to a value smaller than the queue depth. It is recommended to set this frequency to 1 so that the path is switched for each I/O. For more information regarding items that are configured and checked by Host PowerTools, refer to List of items being checked by Host PowerTools.
Creating an iSCSI service
The following steps highlight the configuration for iSCSI.
- Create a network space for the first iSCSI switch.
- Create a new Port Group with an ETH1 port from each node.
- Provide 6 IP addresses for the network space.
- Create a network space for the second iSCSI switch.
- Create a new Port Group with an ETH2 port from each node.
- Provide 6 IP addresses for the network space.
It is recommended to:
- Configure the switch to use a spanning-tree algorithm so that the ports connected to InfiniBox react to network changes.
The switch configuration semantics of many network vendor implementations refer to this as “portfast”, “edge” or “edge-port”.
- Set the link up/down delay to less than 15 seconds.
Cisco calls this delay "debounce", Juniper calls it "hold-time", and HP calls it "link change suppression".
The default link up/down delay for some switches is 60 seconds or more.
- Set the MTU of all your iSCSI switches and hosts to 9000 bytes.
LACP is only advertised after a network space is configured.
- Connect the port to the switches:
- Select one port from each node, and connect it to the iSCSI Switch A.
- Select one port from each node, and connect it to the iSCSI Switch B.
The best practice recommendation is to create two iSCSI network spaces. More than two can be created if needed. For example, if there are multiple VLAN-ed iSCSI data networks, or if more bandwidth is required.
Creating an iSCSI Network Space
Perform the following steps for each of the iSCSI network spaces.
- In the InfiniBox Management Console, click the Settings icon on the left toolbar.
- Select the Network Spaces tab, and click Create.
The Create Network Space step opens.
- Enter a network space name.
- In the Service drop-down menu, select iSCSI.
- (Optional) In the Rate Limit per Node field, you can specify the throughout limit of the network space bandwidth per node, in megabits (not megabytes) per second.
- In the MTU field, enter the size, in bytes, of the Ethernet transfer over the wire. It is recommended to set this to 9000.
- For each node, select its Ethernet interface from the drop-down menu.
If the desired interface is not in the drop-down menu, you can add a new one to the menu. See the Creating Ethernet Interfaces section in this document.
- (Optional) To group the interfaces into a Virtual LAN, click the Create VLAN button.
- Click Next to proceed to the IP Configuration step.
- Enter the networking data:
Enter the first IP address in the network range.
- For each of 6 individual IP addresses or IP ranges in the format 172.16.34.5-12:
Enter an IP address or range within the subnet range, and then click Add to verify the validity of the IP address.
- Click Finish.
The network space is displayed in the window.
Repeat these steps to define an iSCSI service for the second set of Ethernet ports.
Creating Ethernet Interfaces
You can create Ethernet interfaces from the Network Interfaces tab, or from the Create Network Space window.
- In the Create Network Space window, click the Create new option from a node's Ethernet interface field's drop-down menu, or click the Create Interfaces button at the bottom of the window.
The Create Ethernet Interfaces tab opens.
- You can rename the default interface name.
- Select a single port for iSCSI from the available Ethernet ports.
Ports that are already taken by other interfaces are greyed-out.
- Click Create.
- The new interface is now selected in the Create Network Space window.
Configuring iSCSI service parameters
If you want to register iSNS servers, use the iSCSI Settings window to add them. By default, InfiniBox uses the standard iSCSI TCP/IP port (3260) for iSCSI traffic. If you need to use a different TCP/IP port for iSCSI traffic, use the iSCSI Settings window to modify them.
An iSNS server provides a central management point for the group by dynamically maintaining up-to-date information about the iSCSI target names for group volumes. Once the IP address of an iSNS server is entered in an iSCSI initiator’s configuration utility, the setting is persistent across initiator sessions.
- Right-click the iSCSI network space and select iSCSI Settings from the pop-up menu.
The iSCSI Settings window opens.
- Enter the following iSCSI service attributes:
- iSCSI TCP Port
- For each iSNS server IP address or IP range in the format 172.16.34.5-12:
Enter the IP address or range, and then click Add to verify the validity of the IP address.
- Click Done.
iSCSI Client Configuration
iQN = iSCSI Qualified Name is similar to the WorldWide Name (WWN) associated with Fibre Channel devices. It is used as a way to universally identify the node.
Our Host PowerTools with client registration automatically exposes the IQNs to the server. It provides an extremely simple vehicle for proper client configuration and server/client configuration validation. Mapping clients to volumes allows you to simply pick or add the Client iQNs for port connectivity. Advanced performance metrics and analytics are automatically available for FC, iSCSI, and NAS. Best practices suggest that the client use MPIO for balancing I/O across the server IPs (all three controllers).
Viewing the iSCSI network space map
Click the iSCSI service to open its network map. A visual map of the network space and the way it connects the InfiniBox nodes to the switch is displayed.