System Management

This chapter includes the following sections:

Managing DNS Policies

Cisco UCS Central supports global DNS policies defining the DNS server and domain name. Registered Cisco UCS domains choosing to define DNS management globally within that domain's policy resolution control will defer DNS management to its registration with Cisco UCS Central.

Configuring a DNS Policy

Before You Begin

Before configuring a DNS policy in a domain group under the Domain Group root, this policy must first be created. Policies under the Domain Groups root were already created by the system and ready to configure.

Procedure
    Step 1   On the menu bar, click Operations Management.
    Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
    Step 3   Under the Domain Groups root node, click Operational Policies.
    Step 4   In the Navigation pane, click Operational Policies.
    Step 5   In the Work pane, click DNS.
    Step 6   In the Actions area, click Create and complete all applicable fields.
    Step 7   Click Save.

    Deleting a DNS Policy

    Deleting a DNS policy will remove all DNS server settings within that policy.

    Procedure
      Step 1   On the menu bar, click Operations Management.
      Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
      Step 3   Under the Domain Groups root node, click Operational Policies.
      Step 4   In the Navigation pane, click Operational Policies.
      Step 5   In the Work pane, click DNS.
      Step 6   In the Actions area, click Delete.

      A policy that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

      Step 7   Click Save.

      Configuring a DNS Server for a DNS Policy

      Before You Begin

      Configure a DNS policy.

      Procedure
        Step 1   On the menu bar, click Operations Management.
        Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
        Step 3   Under the Domain Groups root node, click Operational Policies.
        Step 4   In the Work pane, click DNS.
        Step 5   In the Actions area, click Add DNS Server and complete all fields.
        1. In the Add DNS Server dialog box, complete all fields.
        2. Click OK.
        Step 6   Click Save.

        Deleting a DNS Server from a DNS Policy

        Procedure
          Step 1   On the menu bar, click Operations Management.
          Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
          Step 3   Under the Domain Groups root node, click Operational Policies.
          Step 4   In the Work pane, click DNS.
          Step 5   In the Actions area, select the DNS server to delete and click Delete.

          You can also right-click the DNS server to access that option.

          Step 6   If Cisco UCS Central GUI displays a confirmation dialog box, click Yes.
          Step 7   Click Save.

          Managing Power Policies

          Cisco UCS Central supports global equipment policies defining the global power allocation policy (based on policy driven chassis group cap or manual blade level cap methods), power policy (based on grid, n+1 or non-redundant methods). Registered Cisco UCS domains choosing to define power management and power supply units globally within that client's policy resolution control will defer power management and power supply units to its registration with Cisco UCS Central.

          Configuring a Global Power Allocation Equipment Policy

          Before You Begin

          Before configuring a global power allocation equipment policy under a domain group, this policy must first be created. Policies under the Domain Groups root were already created by the system and ready to configure.

          Procedure
            Step 1   On the menu bar, click Operations Management.
            Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
            Step 3   Under the Domain Groups root node, click Operational Policies.
            Step 4   In the Navigation pane, click Operational Policies.
            Step 5   In the Work pane, click Equipment.
            Step 6   In the Work pane, click the Global Power Allocation Policy tab.
            Step 7   In the Actions area, click Create and complete all applicable fields.
            Step 8   Click Save.

            Deleting a Global Power Allocation Equipment Policy

            Procedure
              Step 1   On the menu bar, click Operations Management.
              Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
              Step 3   Under the Domain Groups root node, click Operational Policies.
              Step 4   In the Navigation pane, click Operational Policies.
              Step 5   In the Work pane, click Equipment.
              Step 6   In the Work pane, click the Global Power Allocation Policy tab.
              Step 7   In the Actions area, click Delete.

              A policy that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

              Step 8   Click Save.

              Configuring a Power Equipment Policy

              Before You Begin

              Before configuring a power equipment policy under a domain group, this policy must first be created. Policies under the Domain Groups root were already created by the system and ready to configure.

              Procedure
                Step 1   On the menu bar, click Operations Management.
                Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                Step 3   Under the Domain Groups root node, click Operational Policies.
                Step 4   In the Navigation pane, click Operational Policies.
                Step 5   In the Work pane, click Equipment.
                Step 6   In the Work pane, click the Power Policy tab.
                Step 7   In the Actions area, click Create and complete all applicable fields.
                Step 8   Click Save.

                Deleting a Power Equipment Policy

                Procedure
                  Step 1   On the menu bar, click Operations Management.
                  Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                  Step 3   Under the Domain Groups root node, click Operational Policies.
                  Step 4   In the Navigation pane, click Operational Policies.
                  Step 5   In the Work pane, click Equipment.
                  Step 6   In the Work pane, click the Power Policy tab.
                  Step 7   In the Actions area, click Delete.

                  A policy that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

                  Step 8   Click Save.

                  Managing Time Zones

                  Cisco UCS Central supports global date and time policies based on international time zones and defined NTP server. Registered Cisco UCS Manager clients choosing to define date and time globally within that client's policy resolution control will defer the configuration for date and time to its registration with Cisco UCS Central.

                  Configuring a Date and Time Policy

                  Before You Begin

                  Before configuring a date and time policy under a domain group, this policy must first be created. Policies under the Domain Groups root were already created by the system and ready to configure.

                  Procedure
                    Step 1   On the menu bar, click Operations Management.
                    Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                    Step 3   Under the Domain Groups root node, click Operational Policies.
                    Step 4   In the Navigation pane, click Operational Policies.
                    Step 5   In the Work pane, click DateTime.
                    Step 6   In the Actions area, click Create and complete all applicable fields.
                    Step 7   Click Save.

                    Deleting a Date and Time Policy

                    A date and time policy is deleted from a domain group under the domain group root. Date and time policies under the domain groups root cannot be deleted.

                    Deleting a date and time policy will remove all NTP server settings within that policy.

                    Procedure
                      Step 1   On the menu bar, click Operations Management.
                      Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                      Step 3   Expand the node for a domain group containing the policy to delete.
                      Step 4   In the Navigation pane, click Operational Policies.
                      Step 5   In the Work pane, click DateTime.
                      Step 6   In the Actions area, click Delete.

                      A policy that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

                      Step 7   If Cisco UCS Central GUI displays a confirmation dialog box, click Yes.
                      Step 8   Click Save.

                      Configuring an NTP Server for a Date and Time Policy

                      Before You Begin

                      To configure an NTP server for a domain group under the domain group root, a date and time policy must first have been created.

                      Procedure
                        Step 1   On the menu bar, click Operations Management.
                        Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                        Step 3   Under the Domain Groups root node, click Operational Policies.
                        Step 4   In the Work pane, click DateTime.
                        Step 5   In the Actions area, click Add NTP Server and complete all fields and click OK.
                        Step 6   Click Save.

                        Configuring Properties for an NTP Server

                        An existing NTP server's properties may be updated before saving an NTP server instance. To change the name of an NTP server that is saved, it must be deleted and recreated.

                        Procedure
                          Step 1   On the menu bar, click Operations Management.
                          Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                          Step 3   Under the Domain Groups root node, click Operational Policies.
                          Step 4   In the Navigation pane, click Operational Policies.
                          Step 5   In the Work pane, click DateTime.
                          Step 6   In the Actions area, select the NTP server to configure, click Properties and complete all fields.

                          You can also right-click the NTP server to access that option. The Properties (NTP Provider) dialog accessed by clicking Properties in the in the Actions area cannot be edited if the NTP server has been saved. To change the server name of an NTP server that was saved, delete and recreate the NTP server.

                          1. In the Properties (NTP Provider) dialog box, complete all fields.
                            Name Description

                            NTP Server field

                            The IP address or hostname of the NTP server you want to use.

                            Note   

                            If you use a hostname rather than an IPv4 address, you must configure a DNS server. If the Cisco UCS domain is not registered with Cisco UCS Central or DNS management is set to local, configure a DNS server in Cisco UCS Manager. If the Cisco UCS domain is registered with Cisco UCS Central and DNS management is set to global, configure a DNS server in Cisco UCS Central.

                          2. Click OK.
                          Step 7   Click Save.

                          Deleting an NTP Server from a Date and Time Policy

                          Procedure
                            Step 1   On the menu bar, click Operations Management.
                            Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                            Step 3   Under the Domain Groups root node, click Operational Policies.
                            Step 4   In the Work pane, click DateTime.
                            Step 5   In the Actions area, select the NTP server to delete and click Delete.

                            You can also right-click the NTP server to access that option. An NTP server that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

                            Step 6   If Cisco UCS Central GUI displays a confirmation dialog box, click Yes.

                            SNMP Policies

                            Cisco UCS Central supports global SNMP policies enabling or disabling, defining SNMP traps and SNMP users (with regular and privacy passwords, authentication types of md5 or sha, and encryption types DES and AES-128). Registered Cisco UCS domains choosing to define SNMP policies globally within that client's policy resolution control will defer all SNMP policies to its registration with Cisco UCS Central.

                            The SNMP Agent functionality provides the ability to remotely monitor the Cisco UCS Central. You can also change the Cisco UCS Central host IP, and then restart the SNMP agent on the new IP. SNMP is run on both the active and standby Cisco UCS Central servers and the configuration is persisted on both. Cisco UCS Central offers read-only access to only the operating system managed information base (MIB).Through the Cisco UCS Central CLI you can configure the community strings for SNMP v1, v2c, and create and delete the SNMPv3 users.

                            SNMP Functional Overview

                            The SNMP framework consists of three parts:

                            • An SNMP manager—The system used to control and monitor the activities of network devices using SNMP.
                            • An SNMP agent—The software component within Cisco UCS Central, the managed device, that maintains the data for Cisco UCS Central and reports the data, as needed, to the SNMP manager. Cisco UCS Central includes the agent and a collection of MIBs. To enable the SNMP agent and create the relationship between the manager and agent, enable and configure SNMP in Cisco UCS Central.
                            • A managed information base (MIB)—The collection of managed objects on the SNMP agent. Cisco UCS Central supports only the OS MIBs.
                            Cisco UCS Central supports SNMPv1, SNMPv2c and SNMPv3. Both SNMPv1 and SNMPv2c use a community-based form of security. The following RFCs define the SNMP:

                            SNMP Support in Cisco UCS Central

                            Support for MIBs

                            Cisco UCS Central supports read-only access to OS MIBs. No set operations are available for the MIBs. The following MIBs are supported by Cisco UCS Central:

                            • SNMP MIB-2 System
                            • HOST-RESOURCES-MIB
                              • hrSystem
                              • hrStorage
                              • hrDevice
                              • hrSWRun
                              • hrSWRunPerf
                            • UCD-SNMP-MIB
                              • Memory
                              • dskTable
                              • systemStats
                              • fileTable
                            • SNMP MIB-2 Interfaces
                              • ifTable
                            • IP-MIB
                            • SNMP-FRAMEWORK-MIB
                              • snmpEngine
                            • IF-MIB
                            • DISMAN-EVENT-MIB
                            • SNMP MIB-2 snmp

                            Note

                            Cisco UCS Central does not provide support for IPV6 andCisco UCS Central MIBs.

                            Authentication Protocols for SNMPv3 Users

                            Cisco UCS Central supports the following authentication protocols for SNMPv3 users:

                            • HMAC-MD5-96 (MD5)
                            • HMAC-SHA-96 (SHA)

                            AES Privacy Protocol for SNMPv3 Users

                            Cisco UCS Central uses Advanced Encryption Standard (AES) as one of the privacy protocols for SNMPv3 message encryption and conforms with RFC 3826. If AES is disabled but privacy password is set, then DES is used for encryption.

                            If you enable AES-128 configuration and include a privacy password for an SNMPv3 user, Cisco UCS Central uses the privacy password to generate a 128-bit AES key. The AES privacy password can have a minimum of eight characters. If the passphrases are specified in clear text, you can specify a maximum of 64 characters.

                            SNMP Notifications

                            A key feature of SNMP is the ability to generate notifications from an SNMP agent. These notifications do not require that requests be sent from the SNMP manager. Notifications can indicate improper user authentication, restarts, the closing of a connection, loss of connection to a neighbor router, or other significant events.

                            Cisco UCS Central generates SNMP notifications as traps. Traps are less reliable because the SNMP manager does not send any acknowledgment when it receives a trap, and Cisco UCS Central cannot determine if the trap was received.

                            SNMP Security Features

                            SNMPv3 provides secure access to devices by a combination of authenticating and encrypting frames over the network. SNMPv3 authorizes management operations only by configured users and encrypts SNMP messages. The SNMPv3 User-Based Security Model (USM) refers to SNMP message-level security and offers the following services:

                            • Message integrity—Ensures that messages have not been altered or destroyed in an unauthorized manner and that data sequences have not been altered to an extent greater than can occur non-maliciously.
                            • Message origin authentication—Ensures that the claimed identity of the user on whose behalf received data was originated is confirmed.
                            • Message confidentiality and encryption—Ensures that information is not made available or disclosed to unauthorized individuals, entities, or processes.

                            SNMP Security Levels and Privileges

                            SNMPv1, SNMPv2c, and SNMPv3 each represent a different security model. The security model combines with the selected security level to determine the security mechanism applied when the SNMP message is processed.

                            The security level determines the privileges required to view the message associated with an SNMP trap. The privilege level determines whether the message needs to be protected from disclosure or authenticated. The supported security level depends upon which security model is implemented. SNMP security levels support one or more of the following privileges:

                            • noAuthNoPriv—No authentication or encryption
                            • authNoPriv—Authentication but no encryption
                            • authPriv—Authentication and encryption

                            SNMPv3 provides for both security models and security levels. A security model is an authentication strategy that is set up for a user and the role in which the user resides. A security level is the permitted level of security within a security model. A combination of a security model and a security level determines which security mechanism is employed when handling an SNMP packet.

                            SNMP Security Models and Levels

                            The following table describes the combinations of SNMP security models and levels supported in Cisco UCS Central.

                            Table 1  SNMP Security Models and Levels

                            Model

                            Level

                            Authentication

                            Encryption

                            What Happens

                            v1

                            noAuthNoPriv

                            Community string

                            No

                            Uses a community string match for authentication.

                            v2c

                            noAuthNoPriv

                            Community string

                            No

                            Uses a community string match for authentication.

                            v3

                            noAuthNoPriv

                            Username

                            No

                            Uses a username match for authentication.

                            v3

                            authNoPriv

                            HMAC-MD5 or HMAC-SHA

                            No

                            Provides authentication based on the Hash-Based Message Authentication Code (HMAC) Message Digest 5 (MD5) algorithm or the HMAC Secure Hash Algorithm (SHA).

                            v3

                            authPriv

                            HMAC-MD5 or HMAC-SHA

                            DES

                            Provides authentication based on the HMAC-MD5 or HMAC-SHA algorithms. Provides Data Encryption Standard (DES) 56-bit encryption in addition to authentication based on the Cipher Block Chaining (CBC) DES (DES-56) standard.

                            Configuring an SNMP Policy

                            Before You Begin

                            Before configuring a SNMP policy under a domain group, ensure that a SNMP policy is first created. Policies under the Domain Groups root which were already created by the system and are ready to configure.

                            Procedure
                              Step 1   On the menu bar, click Operations Management.
                              Step 2   In the Navigation pane, expand Domain Groups > Domain Group root, or the Domain Group name where you want to create the policy.
                              Step 3   Under the Domain Groups root node, click Operational Policies.
                              Step 4   In the Navigation pane, click Operational Policies.
                              Step 5   In the Work pane, click SNMP.
                              Step 6   In the Actions area, click Create and complete all applicable fields.

                              For Operational Policies under the Domain Group root node, it is not necessary to click Create to complete all applicable fields.

                              1. In the Actions area, click Enabled to choose the Admin State.

                                If Enabled, Cisco UCS Central uses SNMP to monitor the Cisco UCS Central system. Cisco UCS uses SNMP in all Cisco UCS domains included in the domain group if the groups themselves are not configured with SNMP.

                                The default state is Disabled with no fields displayed. Leaving the default state disables the SNMP policy

                              2. Enter the community or the username in the Community/Username field.

                                You can use the default SNMP v1 or v2c community name or SNMP v3 username Cisco UCS includes on any trap messages it sends to the SNMP host. Enter an alphanumeric string between 1 and 32 characters. Do not use @ (at sign), \ (backslash), " (double quote), ? (question mark) or an empty space. The default is public.

                              3. Enter the system contact person information in the System Contact field.

                                The System Contact person is responsible for the SNMP implementation. Enter a string of up to 255 characters, such as an email address or a name and telephone number.

                              4. Enter the system location in the System Location field.

                                The System Location defines the location of the host on which the SNMP agent (server) runs. Enter an alphanumeric string up to 510 characters.

                              Step 7   Click Save.
                              What to Do Next

                              Create SNMP traps and SNMP users.

                              Creating an SNMP Trap

                              Procedure
                                Step 1   On the menu bar, click Operations Management.
                                Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                                Step 3   In the Navigation pane, click Operational Policies.
                                Step 4   In the Work pane, click SNMP.
                                Step 5   In the SNMP Traps area, click Create SNMP Trap and complete all applicable fields in the Create SNMP Trap dialog box.
                                1. Enter the SNMP host IP in the IP Address field.

                                  Cisco UCS sends the trap to the defined IP address.

                                2. Enter the community or the username in the Community/Username field.

                                  You can use the default SNMP v1 or v2c community name or SNMP v3 username Cisco UCS includes on any trap messages it sends to the SNMP host. Enter an alphanumeric string between 1 and 32 characters. Do not use @ (at sign), \ (backslash), " (double quote), ? (question mark) or an empty space. The default is public.

                                3. Enter the port number in the Port field.

                                  Cisco UCS uses the defined port to communicate with the SNMP host for the trap. Enter an integer between 1 and 65535. The default port is 162.

                                4. Click v1, v2c, or v3 to choose the SNMP Version.
                                5. Click trap to choose the SNMP trapType.
                                6. Click auth, no auth, or priv to define the v3Privilege.
                                7. Click OK.
                                Step 6   Click Save.

                                Creating an SNMP User

                                Procedure
                                  Step 1   On the menu bar, click Operations Management.
                                  Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                                  Step 3   In the Navigation pane, click Operational Policies.
                                  Step 4   In the Work pane, click SNMP.
                                  Step 5   In the SNMP Users area, click Create SNMP User and complete all applicable fields in the Create SNMP User dialog.
                                  1. Enter the SNMP username in the Name field. Enter up to 32 letters or numbers. The name must begin with a letter and you can also specify _ (underscore), . (period), @ (at sign), and - (hyphen).
                                    Note   

                                    You cannot create an SNMP username that is identical to locally authenticated username.

                                  2. Click md5 or sha to chose the authorization type.
                                  3. Check the AES-128 checkbox.

                                    If checked, this user uses AES-128 encryption.

                                  4. Enter the user password in the Password field.
                                  5. Re-enter the user password in the Confirm Password field.
                                  6. Enter the privacy password for this user in the Privacy Password field.
                                  7. Re-enter the privacy password for this user in the Confirm Privacy Password field.
                                  8. Click OK.
                                  Step 6   Click Save.

                                  Deleting an SNMP Policy

                                  A SNMP policy is deleted from a domain group under the domain group root. SNMP policies under the domain groups root cannot be deleted.

                                  Deleting an SNMP policy will remove all SNMP trap and SNMP User settings within that policy.

                                  Procedure
                                    Step 1   On the menu bar, click Operations Management.
                                    Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                                    Step 3   Under the Domain Groups root node, click Operational Policies.
                                    Step 4   In the Navigation pane, click Operational Policies.
                                    Step 5   In the Work pane, click SNMP.
                                    Step 6   In the Actions area, click Delete.

                                    A policy that is deleted will inherit its settings from its domain group's parent until it is reconfigured.

                                    Step 7   Click Save.

                                    Deleting an SNMP Trap

                                    Procedure
                                      Step 1   On the menu bar, click Operations Management.
                                      Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                                      Step 3   In the Navigation pane, click Operational Policies.
                                      Step 4   In the Work pane, click SNMP.
                                      Step 5   In the SNMP Traps area, select the SNMP trap to delete and click Delete.

                                      You can also right-click the SNMP trap to access that option.

                                      Step 6   Click Save.

                                      Deleting an SNMP User

                                      Procedure
                                        Step 1   On the menu bar, click Operations Management.
                                        Step 2   In the Navigation pane, expand Domain Groups > Domain Group root.
                                        Step 3   In the Navigation pane, click Operational Policies.
                                        Step 4   In the Work pane, click SNMP.
                                        Step 5   In the SNMP Users area, select the SNMP user to delete and click Delete.

                                        You can also right-click the SNMP user to access that option.

                                        Step 6   Click Save.

                                        About High Availability in Cisco UCS Central

                                        Cisco UCS Central provides high availability in a cluster setup when you deploy Cisco UCS Central in two virtual nodes. High availability provides stability and redundancy directly to your Cisco UCS Central and indirectly to your Cisco UCS Domains management. The high availability in Cisco UCS Central provides you the following:

                                        • Simplified large scale Cisco UCS deployments with an increased number of servers, chassis, fabric interconnects, and data centers.
                                        • UCS Central VM redundancy in a Hypervisor independent environment.
                                        • A shared storage device to house database and image repositories.
                                        • Built-in failure detection (DME, VM, host, or network failures) and automatic failover to ensure continuous operation.

                                        High Availability Architecture

                                        You will deploy Cisco UCS Central in two VMs on separate hosts to enable high availability. High availability -

                                        • Requires at least one Cisco UCS Manager be registered with Cisco UCS Central for a cluster to support high availability
                                        • Uses the same subnet for individual VMs and VIP addresses
                                        • Allows you to configure a mirrored, multi-path shared storage disk on each VM that is accessible from both hosts
                                        • Uses UCS Manager to store quorum data and determine primary node.
                                        • Exchanges information such as heartbeat and election protocols in the same way as Cisco UCS Manager. This results in a simpler design, more code reusability, and easy to define failover conditions

                                        Cautions and Guidelines for Using High Availability

                                        The following are the guidelines to setup Cisco UCS Central in high availability:

                                        • Make sure both VMs in the cluster should never be on the same server. Otherwise, a single host failure would end up bringing down the cluster.
                                        • Each node in the cluster must have the following:
                                          • A primary NIC connected to the production network that is used for communicating with Cisco UCS Manager, and for heartbeat communications, with the peer node in the cluster.
                                          • A host bus adapter connected to the Storage Area Network (SAN), that is used to access the storage target.
                                        • Separate network path for management and storage network: Make sure the management network used communications between the two Cisco UCS Central nodes are not on the same network as the network that the nodes use to access the shared disk array. The primary heartbeat mechanism relies on exchanging datagrams across the management network. The secondary heartbeat mechanism uses quorum data on Cisco UCS Manager. When you use separate network paths for management and shared disk access, that provides redundant paths between the two nodes making it easier to distinguish node failures from link failures.

                                          Note

                                          High availability is supported only in IPv4 addressing without the DHCP. You must configure the node IPs and cluster VIPs statically during the installation. These IP addresses are allocated from the production network over which the UCS Central cluster communicates with UCSMs.

                                        • Both VMs must be configured on IP addresses that belongs to the same subnet.
                                        • Make sure the cluster node infrastructure does not have a single point of failure. You can connect the cluster nodes my multiple, distinct networks. You can also construct the network with redundant switches and routers or similar hardware that removes single points of failure.
                                        • For high availability Cisco UCS Central supports the most commonly used bus types, such as SAS , Fiber Channel (FC), and iSCSI. SCSI compatibility with Persistent Reservations (PRs) is recommended. LUN masking or zoning should be used to isolate the storage volumes accessed by the cluster from other hosts on the network.