2 Server and Network Preinstallation Tasks

This chapter describes the tasks that you must complete before you start Oracle Universal Installer (OUI) to install Oracle Clusterware and Oracle Real Application Clusters (Oracle RAC) on Microsoft Windows x86 (32-bit) systems.

This chapter includes the following topics:

2.1 Installation Differences Between Windows and Linux or UNIX

If you are experienced with installing Oracle components in Linux or UNIX environments, note that many manual setup tasks required on Linux or UNIX are not required on Windows. The key differences between Windows and Linux or UNIX and installations are:

  • Startup and shutdown services

    With Windows, Oracle Universal Installer creates and sets startup and shutdown services at installation time. On Linux and UNIX systems, administrators are responsible for creating these services.

  • Environment variables

    With Windows, Oracle Universal Installer sets environment variables such as PATH, ORACLE_BASE, ORACLE_HOME, and ORACLE_SID in the registry. On Linux and UNIX systems, you must manually set these environment variables.

  • DBA account for database administrators

    With Windows, Oracle Universal Installer creates the ORA_DBA group. On Linux and UNIX systems, you must create the DBA account manually.

  • Account for running Oracle Universal Installer

    With Windows, you log in with Administrator privileges. You do not need a separate account. On Linux and UNIX systems, you must create this account manually.

See Also:

"Oracle Database Windows/UNIX Differences," in Oracle Database Platform Guide for Microsoft Windows

2.2 Reviewing Upgrade Best Practices

If you have an existing Oracle installation, then document version numbers, patches, and other configuration information, and review upgrade procedures for your existing installation. Review Oracle upgrade documentation before proceeding with installation, to decide how you want to proceed.

The following information applies when upgrading clusters:

  • If servers run the same operating system binary, then Oracle Clusterware and Oracle Real Application Clusters support servers with different hardware in the same cluster. For example, you can build a cluster using different speeds and size computers, if all cluster members are running the 2.6.24 kernel. In addition, during rolling upgrades of the operating system, Oracle supports using different operating system binaries when both versions of the operating system are certified with the version of Oracle Database you are running.

    Note:

    Using mixed operating system versions is only supported for the duration of an upgrade, over the period of a few hours. Oracle does not support operating a cluster with mixed operating systems for an extended period. Oracle does not support running Oracle Clusterware and Oracle Real Application Clusters on heterogeneous platforms (servers with different chip architectures) in the same cluster.
  • Running 32-bit and 64-bit Oracle software versions in the same cluster stack is not supported.

To find the most recent updates, and to find best practices recommendations about preupgrade, post-upgrade, compatibility, and interoperability, refer to "Oracle Upgrade Companion." "Oracle Upgrade Companion" is available through Note 466181.1 on My Oracle Support:

http://metalink.oracle.com

2.3 Checking Hardware and Software Certification

The hardware and software requirements included in this installation guide were current at the time this guide was published. However, because new platforms and operating system software versions might be certified after this guide is published, review the certification matrix on the My Oracle Support Web site for the most up-to-date list of certified hardware platforms and operating system versions. This Web site also provides compatible client and database versions, patches, and workaround information for bugs. The OracleMetaLink Web site is available at the following URL:

https://metalink.oracle.com/

You must register online before using OracleMetaLink. After logging in, select Certify & Availability from the left-hand column. From the Product Lifecycle page, select the Certifications button. Other Product Lifecycle options include Product Availability, Desupport Notices, and Alerts.

The following sections list the following certification information:

2.3.1 Web Browser Support

On 32-bit Windows systems, the following Web browsers are supported for Oracle Enterprise Manager Database Control:

  • Netscape Navigator 7.2 and higher

  • Microsoft Internet Explorer 6.0 with service pack 2, and higher

  • Mozilla version 1.7 and higher

  • Firefox versions 1.0.4, 1.5, 2. 0 and higher

To view or develop Oracle Application Express applications, Web browsers must support Java Script and the HTML 4.0, and CSS 1.0 standards. The following browsers meet this requirement:

  • Microsoft Internet Explorer 6.0 or later version

  • Firefox 1.0 or a later version

2.3.2 Telnet and Terminal Services Support

This section contains these topics:

2.3.2.1 Windows Telnet Services Support

Windows 2000 and Windows Server 2003 can use a Telnet Service to enable remote users to log on to the operating system and run console programs using the command line. Oracle supports the use of database command line utilities such as sqlplus, export, import and sqlldr using this feature, but does not support the database GUI tools such as Oracle Universal Installer, Database Configuration Assistant, and Oracle Net Configuration Assistant.

Note:

Ensure that the Telnet service is installed and started.

2.3.2.2 Windows Terminal Services and Remote Desktop Support

Oracle supports installing, configuring, and running Oracle Database through Terminal Services (console mode), on Windows 2000 and Windows 2003 Server. If you do not use Terminal Services in console mode, then you will encounter problems with configuration assistants at the end of the installation.

To start Terminal Services in console mode, enter the following command:

mstsc -v:servername /F /console

Platform-specific support information is as follows:

  • Windows 2000: Oracle supports installing, configuring, and running Oracle Database from a remote Terminal Services Client.

  • Windows Server 2003: You can configure Windows Server 2003 to use Terminal Services in Remote Desktop for Administration Mode or Terminal Server Mode.

The following products and features are not supported with Windows Terminal Services:

  • Oracle Connection Manager

  • Oracle Object Link Manager

  • Oracle Services for Microsoft Transaction Server

  • Server Management (SRVM) (You need to use a Windows Terminal Services console in order to use SRVM.)

See Also:

2.4 Checking Hardware Requirements

You must have at least the following hardware component values for installing Oracle Database:

  • RAM: At least 1 GB

  • Virtual memory: double the amount of RAM

  • Hard disk space: See Table 2-1

  • Temp disk space: 400 MB

  • Video adapter: 256 color

  • Processor: 550 MHz minimum for 32-bit

Note:

Oracle provides 32-bit (x86) and 64-bit (x64) versions of Oracle Real Application Clusters for Microsoft Windows. The 32-bit database version runs on the 32-bit version of Windows on either x86 or x64 hardware.

2.4.1 Hard Disk Space Requirements

Oracle recommends that you store Oracle components on NTFS. Because it is difficult for OUI to estimate NTFS and FAT disk sizes on Windows, the system requirements in this section are likely more accurate than the values reported on the Oracle Universal Installer Summary screen. In other words, it is difficult for OUI to provide accurate hard disk values for disk space. This includes the space required to create databases that are over 700 MB in size and the sizes of compressed files that are expanded on the hard drive.

Note:

Oracle Clusterware software cannot be installed on NFS.

Data files are not placed on NTFS partitions because they cannot be shared. Data files can be placed on unformatted (raw) disks used by ASM, Oracle Cluster File System (OCFS), or shared unformatted disks. Oracle Clusterware shared files can be placed only on OCFS or shared unformatted disks.

ASM is recommended for managing Oracle database datafiles in single instance or Oracle Real Application Cluster (Oracle RAC) environments. OCFS is best suited for Oracle binaries (if using a shared Oracle home) and flat files such as alert log and trace files.

To install Oracle Clusterware, it requires 650 MB of available disk space for the software binaries. For the shared files used by Oracle Clusterware, you must have either 1.1 GB of available disk space if using external redundancy for the disks or 1.4 GB of available disk space if using the redundancy features available with Oracle Clusterware.

For both the Enterprise and Standard Editions of Oracle RAC, the hard disk requirements for Oracle Database components include 32 MB required to install Java Runtime Environment (JRE) and OUI on the partition where the operating system is installed. If sufficient space is not detected, then the installation fails and an error message appears. Table 2-1 lists the hard disk space requirements, including the requirement for the starter database.

Table 2-1 Hard Disk Space Requirements for Oracle RAC

Installation Type TEMP space SYSTEM_DRIVE:\Program Files\Oracle Oracle Database Home Data FilesFoot 1  Total

Standard Edition

400 MB

100 MB

2.95 GB

3 GBFoot 2 

6.45 GB

Enterprise Edition

400 MB

100 MB

2.96 GB

3 GB

6.46 GB


Footnote 1 Refers to the contents of the admin, flash_recovery_area, and oradata directories in the ORACLE_BASE directory

Footnote 2 This size can be greater, depending on the installation options selected, such as languages or additional components. If you later plan to install Oracle Database and Oracle Real Application Clusters with automated backups enabled, then include at least an additional 2 GB for data file disk space.

2.5 Verifying Hardware Requirements

To ensure that the system meets these requirements, follow these steps:

  1. Determine the physical RAM size. For a computer using Windows 2003, for example, open System in the control panel and select the General tab. If the size of the physical RAM installed in the system is less than the required size, then you must install more memory before continuing.

  2. Determine the size of the configured swap space (also known as paging file size). For a computer using Windows 2003, for example, open System in the control panel, select the Advanced tab, and click Settings in the Performance section.

    If necessary, refer to your operating system documentation for information about how to configure additional swap space.

  3. Determine the amount of free disk space on the system. For a computer using Windows 2003, for example, open My Computer, right-click the drive where the Oracle software is to be installed, and choose Properties.

  4. Determine the amount of disk space available in the temp directory. This is equivalent to the total amount of free disk space, minus what will be needed for the Oracle software to be installed.

    You require 400 MB of disk space available in the temp directory. If you do not have sufficient space, then first delete all unnecessary files. If the temp disk space is still less than the required amount, then set the TEMP or TMP environment variable to point to a different hard drive. For a computer using Windows 2003, for example, open the System control panel, select the Advanced tab, and click Environment Variables.

    Note:

    The temporary directory must reside in the same directory path on each node in the cluster.

2.6 Checking Software Requirements

Table 2-2 lists the software requirements for Oracle Clusterware and Oracle RAC 11g release 1.

Table 2-2 Oracle RAC Software Requirements for Windows Systems

Requirement Value

System Architecture

Processor: Intel (x86), AMD64, or Intel Extended memory (EM64T)

Note: Oracle provides 32-bit (x86), 64-bit (Itanium), versions of Oracle Database with Oracle Real Application Clusters (Oracle RAC) for Windows.

The 32-bit RAC version runs on the 32-bit version of Windows. For additional information, visit My Oracle Support at the following URL:

https://metalink.oracle.com

Operating System for 32-bit Windows

Oracle Real Application Clusters for 32-bit Windows:

  • Windows 2000 (32-bit) with service pack 1 or higher. All editions, including Terminal Services and Windows 2000 MultiLanguage Edition (MLE), are supported.

  • Windows Server 2003 (32-bit), all editions.

  • Windows Server 2003 R2 (32-bit), all editions.

    Windows Multilingual User Interface Pack is supported on Windows Server 2003 and Windows Server 2003 R2.

  • Windows Server 2008 (32-bit), all editions. Oracle does not support the following two operating system features: Windows Server 2008 Hyper-V and Server Core.

Compiler for 32-bit Windows

Pro*Cobol is supported with Micro Focus Net Express 5.0. Object Oriented COBOL (OOCOBOL) specifications are not supported.

The following components are supported with the Microsoft Visual C++ .NET 2002 7.0 and Microsoft Visual C++ .NET 2003 7.1 compilers:

  • Oracle C++ Call Interface

  • Oracle Call Interface

  • Pro*C/C++

  • External callouts

  • Oracle XML Developer's Kit (XDK)

Network Protocol

Oracle Net foundation layer uses Oracle protocol support to communicate with the following industry-standard network protocols:

  • TCP/IP

  • TCP/IP with SSL

  • Named Pipes


Note:

The Clusterware API Demo program is not supported on Microsoft Windows.

If you are currently running an operating system version that is not supported by Oracle Database 11g, release 11.1, such as Windows NT Server 4.0, then you must first upgrade your operating system before upgrading to Oracle Database 11g Real Application Clusters.

If you are currently running a cluster with Oracle9i Clusterware and wish to continue to use it, then you must upgrade to Oracle9i, version 9.2.0.4 to ensure compatibility between Cluster Manager Services in Oracle9i and Oracle Database 11g.

2.7 Configuring User Accounts

To install and perform administrative tasks, Oracle recommends using the same local administrative user name and password on every node in a cluster, or the same domain user name with local administrative privileges on all nodes. All nodes must be in the same domain.

Note:

If you change the user name or domain name that was used to install Oracle Clusterware after you install the product, then Oracle Clusterware services will not start properly.

If you use a domain account for the installation, then the domain user must be explicitly granted local administrative privileges on each node in the cluster. It is not sufficient if the domain user has inherited privileges from membership in a group.

Note:

Do not install Oracle RAC on a primary domain controller or backup domain controller. Although this type of installation might succeed, your system may experience many resource contention issues.

2.7.1 Managing User Accounts with User Account Control

To ensure that only trusted applications run on your computer, Windows Server 2008 provides User Account Control. If you have enabled this security feature, then depending on how you have configured it, Oracle Universal Installer prompts you for either your consent or your credentials when installing Oracle Database. Provide either the consent or your Windows Administrator credentials as appropriate.

You must have Administrator privileges to run some Oracle tools, such as Database Configuration Assistant, Net Configuration Assistant, and OPatch, or to run any tool or application that writes to any directory within the Oracle home. If User Account Control is enabled and you are logged in as the local Administrator, then you can successfully run each of these commands. However, if you are logged in as "a member of the Administrator group," then you must explicitly invoke these tasks with Windows Administrator privileges.

All of the Oracle shortcuts that require Administrator privileges are invoked as "Administrator" automatically when you click the shortcuts. However, if you run the previously mentioned tools from a Windows command prompt, then you need to run them from an Administrative command prompt. OPatch does not have a shortcut and has to be run from an Administrative command prompt.

2.8 Checking Network Requirements

Check that you have the networking hardware and internet protocol (IP) addresses required for an Oracle RAC installation.

Note:

For the most up-to-date information about supported network protocols and hardware for Oracle RAC installations, refer to the Certify pages on the OracleMetaLink Web site:
https://metalink.oracle.com

2.8.1 Network Hardware Requirements

Each node in the cluster must meet the following requirements:

  • Each node must have at least two network adapters; one for the public network interface and one for the private network interface (the interconnect).

  • The private and public private network connection names must be different from each other and cannot contain any multibyte language characters. The names are case-sensitive.

  • The private network connection name must be the same on all nodes.

  • The public network connection name must be the same on all nodes.

  • The public interface on each node must be listed first in the bind order (the order in which network services access the node).

  • Oracle supports the TCP/IP protocol for the public and private networks

  • Windows Media Sensing must be disabled for the private network connection by setting the value of the DisableDHCPMediaSense parameter to 1.

2.8.2 IP Address Requirements

Before starting the installation, you must have the following IP addresses available for each node:

  • An IP address with an associated network name registered in the domain name service (DNS) for the public interface. If you do not have an available DNS, then record the network name and IP address in the system hosts file, %SystemRoot%\system32\drivers\etc\hosts.

  • One virtual IP (VIP) address with an associated network name registered in DNS. If you do not have an available DNS, then record the network name and VIP address in the system hosts file, %SystemRoot%\system32\drivers\etc\hosts. Select an address for your VIP that meets the following requirements:

    • The IP address and network name are currently unused

    • The VIP is on the same subnet as your public interface

    Before installation, ensure that the default gateway can be accessed by a ping command. To find the default gateway, use the route print command, as described in your operating system's Help utility. After installation, configure clients to use either the VIP address or the network name associated with the VIP. If a node fails, then the node's virtual IP address fails over to another node.

  • A private IP address with a host name for each private interface.

    Oracle recommends that you use private network IP addresses for these interfaces (for example: 10.*.*.* or 192.168.*.*). Use the %SystemRoot%\system32\drivers\etc\hosts file on each node to associate private network names with private IP addresses.

    Note:

    Avoid changing host names after you complete the Oracle Clusterware installation, including adding or deleting domain qualifications. You must remove the node from the cluster configuration and add it back later with the new name.

For example, with a two-node cluster where each node has one public and one private interface, you might have the configuration shown in the following table for your network interfaces, where the hosts file is %SystemRoot%\system32\drivers\etc\hosts:

Node Interface Name Type IP Address Registered In
rac1 rac1 Public 143.46.43.100 DNS (if available, else the hosts file)
rac1 rac1-vip Virtual 143.46.43.104 DNS (if available, else the hosts file)
rac1 rac1-priv Private 10.0.0.1 Hosts file
rac2 rac2 Public 143.46.43.101 DNS (if available, else the hosts file)
rac2 rac2-vip Virtual 143.46.43.105 DNS (if available, else the hosts file)
rac2 rac2-priv Private 10.0.0.2 Hosts file

To enable VIP failover, the configuration shown in the preceding table defines the public and VIP addresses of both nodes on the same subnet, 143.46.43.0. When a node or interconnect fails, then the associated VIP is relocated to the surviving instance, enabling fast notification of the failure to the clients connecting through that VIP. If the application and client are configured with transparent application failover options, then the client is reconnected to the surviving instance.

2.8.3 Checking Network Requirements

To verify that the network hardware is configured correctly for each node, you must perform the following tasks:

2.8.3.1 Check Hardware and IP Addresses

To verify that each node meets the requirements, follow these steps:

  1. If necessary, install the network adapters for the public and private networks and configure them with either public or private IP addresses.

  2. Register the host names and IP addresses for the public network interfaces in DNS.

  3. For each node, register one virtual host name and IP address in DNS.

  4. For each private interface on every node, add a line similar to the following to the %SystemRoot%\system32\drivers\etc\hosts file on all nodes, specifying the private IP address and associated private host name:

    10.0.0.1     rac1-priv
    

2.8.3.2 (Optional) Rename Network Interfaces

If you need to change a network interface name, follow these steps:

  1. Click Start, then Settings, then Control Panel, and then Network and Dial-up Connections

  2. Right click the icon of the network interface for which you need to change the name

  3. Select Rename

  4. Enter and save the new name

2.8.3.3 Configure Network Bind Order

To ensure that your public interface is first in the bind order, follow these steps:

  1. Right-click My Network Places and choose Properties.

  2. In the Advanced menu, click Advanced Settings...

  3. If the public interface name is not the first name listed under the Adapters and Bindings tab, then select it and click the arrow to move it to the top of list

  4. Click OK to save the setting and then exit network setup dialog

2.8.3.4 Disable Windows Media Sensing for TCP/IP

To disable Windows Media Sensing for TCP/IP, you must set the value of the DisableDHCPMediaSense parameter to 1 on each node. Because you need to modify the Windows registry to disable Media Sensing, you should first backup the registry and confirm that you can restore it, using the methods described in your Windows documentation. Disable Media Sensing by completing the following steps on each node of your cluster:

  1. Backup the Windows registry.

  2. Use Registry Editor (Regedt32.exe) to view the following key in the registry:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
    
  3. Add the following registry value:

    Value Name: DisableDHCPMediaSense
    Data Type: REG_DWORD -Boolean
    Value: 1
    
  4. Restart the computer.

2.9 Checking Individual Component Requirements

This section contains these topics:

2.9.1 Oracle Advanced Security Requirements

Satisfy hardware and software requirements to use authentication support with Oracle components. Some Oracle Advanced Security components can use a Lightweight Directory Access Protocol (LDAP) such as Oracle Internet Directory.

2.9.2 Oracle Enterprise Manager Requirements

All Oracle Enterprise Manager products that you use on your system must be of the same release. Older versions of Enterprise Manager are not supported with the current release.

Note:

All Oracle Enterprise Manager products, except Oracle Enterprise Manager Database Control, are released on the Enterprise Manager Grid Control installation media. Enterprise Manager Database Control is available on the Oracle Database installation media.

See Also:

Oracle Enterprise Manager Grid Control Installation and Basic Configuration available on the Enterprise Manager Grid Control installation media

2.10 Verifying Cluster Privileges

Before running Oracle Universal Installer, from the node where you intend to run the Installer, verify that you have administrative privileges on the other nodes. To do this, enter the following command for each node that is a part of the cluster where nodename is the node name:

net use \\nodename\C$

If your installation accesses drives in addition to the C: drive, then repeat this command for every node in the cluster, substituting the drive letter for each drive you plan to use.

Note:

For the installation to be successful, you must use the same local administrative user name and password on every node in a cluster or the same domain user name with local administrative privileges on all nodes.

If you use a domain account for the installation, then the domain user must be explicitly granted local administrative privileges on each node in the cluster. It is not sufficient if the domain user has inherited privileges from membership in a group.

2.11 Understanding and Using Cluster Verification Utility

Cluster Verification Utility (CVU) is a tool that performs system checks. This guide provides CVU commands to assist you with confirming that your system is properly configured for Oracle Clusterware and Oracle RAC installation.

This section describes the following topics:

2.11.1 Entering Cluster Verification Utility Commands

CVU is provided with two scripts: runcluvfy.bat, which is designed to be used before installation, and cluvfy, which is in the path CRS_home\bin. The script runcluvfy.bat contains temporary variable definitions which enable it to be run before installing Oracle Clusterware or Oracle Database. After you install Oracle Clusterware, use the command cluvfy to check prerequisites and perform other system readiness checks.

Before Oracle software is installed, to enter a CVU command, change directories and start runcluvfy.bat using the following syntax:

cd mountpoint
runcluvfy.bat options

In the preceding example, the variable mountpoint represents the path for the installation media and the variable options represents the CVU command options that you select. For example:

C:\> cd d:\media\db\Disk1\
C:\> runcluvfy.bat comp nodereach -n node1,node2 -verbose

By default, when you enter a CVU command, CVU provides a summary of the test. During preinstallation, Oracle recommends that you obtain detailed output by using the -verbose argument with the CVU command. The -verbose argument produces detailed output of individual checks. Where applicable, it shows results for each node in a tabular layout.

2.11.2 Using CVU to Determine if Installation Prerequisites are Complete

You can use CVU to determine which system prerequisites for installation are already completed. Use this option if you are installing Oracle 11g release 1 (11.1) on a system with a pre-existing Oracle software installation. In using this option, note the following:

  • You must complete the prerequisites for using CVU, notably configuring SSH between all nodes in the cluster, before you can complete a cluster-wide status check.

  • CVU can assist you by finding preinstallation steps that need to be completed, but it cannot perform preinstallation tasks

Use the following syntax to determine what preinstallation steps are completed, and what preinstallation steps must be performed

runcluvfy.bat stage -pre crsinst -n node_list 

In the preceding syntax example, replace the variable node_list with the names of the nodes in your cluster, separated by commas.

For example, for a cluster with the installation media located at D:\media\db and consisting of nodes node1, node2, and node3, you would enter the following command:

C:\> cd d:\media\db\Disk1\
D:\> runcluvfy.bat stage -pre crsinst -n node1,node2,node3

Review the CVU report, and proceed to the sections of the preinstallation chapter to complete additional steps as needed.

2.11.3 Using the Cluster Verification Utility Help

The cluvfy commands have context-sensitive help that shows correct syntax usage based on the command line arguments that you enter.

If you enter an invalid CVU command, then CVU shows the correct usage for that command. For example, if you type runcluvfy.bat stage -pre dbinst, then CVU shows the correct syntax for the database preinstallation checks that CVU performs with the dbinst stage option. The following is a list of context help commands.

  • cluvfy -help —CVU displays detailed CVU command information.

  • cluvfy comp -list—CVU displays a list of components that can be checked, and brief descriptions of how each component is checked.

  • cluvfy comp -help—CVU displays detailed syntax for each of the valid component checks.

  • cluvfy stage -list—CVU displays a list of valid stages.

  • cluvfy stage -help—CVU displays detailed syntax for each of the valid stage checks.

2.11.4 Using Cluster Verification Utility with Oracle Database 10g Release 1 or 2

You can use CVU on the Oracle Database 11g release 1 (11.1) media to check system requirements for Oracle Database 10g release 1 (10.1) and later installations. To use CVU to check 10. 2 installations, append the command flag -r 10gR2 to the standard CVU system check commands.

For example, to perform a verification check for a Cluster Ready Services 10. 2 installation, on a system where the installation media is located on drive D: and the cluster nodes are node1, node2, and node3, enter the following command:

C:\> cd d:\Disk1\
D:\> runcluvfy.bat stage -pre crsinst -n node1,node2,node3 -r 10gR2

Note:

If you do not specify a release version to check, then CVU checks for 11g release 1 (11.1) requirements.

2.11.5 Verbose Mode and "Unknown" Output

If you run CVU using the -verbose argument, and a CVU command responds with UNKNOWN for a particular node, then this is because the CVU cannot determine whether a check passed or failed. The following is a list of possible causes for an "Unknown" response:

Note:

For Windows Server 2008, you must have administrator privileges and you must run commands from an Administrative command prompt to run executables that reside in the Oracle Clusterware home.
  • The node is down

  • Executables required by CVU are missing in the Oracle_home\BIN directory, where Oracle_home represents the Oracle Clusterware home or the Oracle Database home directory

  • The user account starting CVU does not have privileges to run common operating system executables on the node

  • The node is missing an operating system patch, or other required software