mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 13. Minimizing or avoiding system slowdowns due to journaling The order in which journal changes are written to disk might differ from the order in which they arrive. The kernel I/O system can reorder the journal changes to optimize the use of available storage space. Journal activity can result in system latency by re-ordering journal changes and committing data and metadata. As a result, journaling file systems can slow down the system. XFS is the default file system used by RHEL 8. This is a journaling file system. An older file system called ext2 does not use journaling. Unless your organization specifically requires journaling, consider the ext2 file system. In many of Red Hat's best benchmark results, the ext2 filesystem is used. This is one of the top initial tuning recommendations. Journaling file systems like XFS , records the time a file was last accessed (the atime attribute). If you need to use a journaling file system, consider disabling atime . 13.1. Disabling atime Disabling the atime attribute increases performance and decreases power usage by limiting the number of writes to the file-system journal. Procedure Open the /etc/fstab file using your chosen text editor and locate the entry for the root mount point. Edit the options sections to include the terms noatime and nodiratime . The noatime option prevents access timestamps being updated when a file is read, and the nodiratime option stops directory inode access times being updated. Important Some applications rely on atime being updated. Therefore, this option is reasonable only on systems where such applications are not used. Alternatively, you can use the relatime mount option, which ensures that the access time is only updated if the access time is older than the current modify time. 13.2. Additional resources mkfs.ext2(8) , mkfs.xfs(8) , and mount(8) man pages on your system

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/dev/mapper/rhel-root / xfs defaults...
/dev/mapper/rhel-root / xfs noatime,nodiratime...
4.320. telnet 4.320.1. RHBA-2011:0963 - telnet bug fix update Updated telnet packages that fix one bug are now available for Red Hat Enterprise Linux 6. Telnet is a popular protocol for logging in to remote systems over the Internet. The telnet-server package includes a telnet service that supports remote logins into the host machine. The telnet service is disabled by default. Bug Fix BZ# 678324 Prior to this update, the in.telnetd service used the sockaddr structure to store IPv6 addresses. This structure was too small in its size, and as a result, subsequent logins wrote incorrect records about the last login source. With this update, in.telnetd now uses the sockaddr_storage structure, which is large enough in its size to be able to store IPv6 addresses. All users of telnet are advised to upgrade to these updated packages, which fix this bug.

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5.7.3.2. File Sharing When multiple users need to share a single copy of a file, allowing access by making changes to file permissions is not the best approach. It is far preferable to formalize the file's shared status. There are several reasons for this: Files shared out of a user's directory are vulnerable to disappearing unexpectedly when the user either leaves the organization or does nothing more unusual than rearranging their files. Maintaining shared access for more than one or two additional users becomes difficult, leading to the longer-term problem of unnecessary work required whenever the sharing users change responsibilities. Therefore, the preferred approach is to: Have the original user relinquish direct ownership of the file Create a group that will own the file Place the file in a shared directory that is owned by the group Make all users needing access to the file part of the group Of course, this approach would work equally well with multiple files as it would with single files, and can be used to implement shared storage for large, complex projects.

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7.42. dstat 7.42.1. RHEA-2015:1290 - dstat enhancement update An updated dstat package that adds one enhancement is now available for Red Hat Enterprise Linux 6. The dstat package provides a replacement for the vmstat, iostat, and netstat tools. The dstat tool can be used for performance tuning tests, benchmarks, and troubleshooting. Enhancement BZ# 766443 The dstat utility has been enhanced to support the use of symbolic links as its parameters. This allows users to dynamically specify the boot device name, which ensures that dstat displays correct information after hot plugs and similar operations. Users of dstat are advised to upgrade to this updated package, which adds this enhancement.

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1.11. Additional Resources This section includes various resources that can be used to learn more about the philosophy of system administration and the Red Hat Enterprise Linux-specific subject matter discussed in this chapter. 1.11.1. Installed Documentation The following resources are installed in the course of a typical Red Hat Enterprise Linux installation and can help you learn more about the subject matter discussed in this chapter. crontab(1) and crontab(5) man pages -- Learn how to schedule commands and scripts for automatic execution at regular intervals. at(1) man page -- Learn how to schedule commands and scripts for execution at a later time. bash(1) man page -- Learn more about the default shell and shell script writing. perl(1) man page -- Review pointers to the many man pages that make up perl's online documentation. python(1) man page -- Learn more about options, files, and environment variables controlling the Python interpreter. gedit(1) man page and Help menu entry -- Learn how to edit text files with this graphical text editor. emacs(1) man page -- Learn more about this highly-flexible text editor, including how to run its online tutorial. vim(1) man page -- Learn how to use this powerful text editor. Mozilla Help Contents menu entry -- Learn how to edit HTML files, read mail, and browse the Web. evolution(1) man page and Help menu entry -- Learn how to manage your email with this graphical email client. mutt(1) man page and files in /usr/share/doc/mutt- <version> -- Learn how to manage your email with this text-based email client. pam(8) man page and files in /usr/share/doc/pam- <version> -- Learn how authentication takes place under Red Hat Enterprise Linux.

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Chapter 1. Overview of automated rules You can use automated rules to enable JFR to continuously monitor a running target application. You do not need to restart or redeploy the application. Continuous monitoring event templates exist in Cryostat that you can use to create automated rules and templates. By using continuous monitoring event templates, you can reduce any downtime for specifying a JFR to continuously monitoring an application. You can define automated rules regardless of whether you configure your target applications to use a Java Management Extensions (JMX) connection or an agent HTTP API connection. For more information about configuring your target applications, see Configuring Java applications . Consider the following guidelines: If your target JVMs use an agent HTTP API connection, ensure that you set the cryostat.agent.api.writes-enabled property to true in your target application's configuration. Otherwise, the Cryostat agent cannot accept on-demand requests to start, stop, and delete JFR recordings based on automated rules. If your target JVMs use a JMX connection, before you create an automated rule that applies to multiple target JVMs that each require JMX credentials, consider storing credentials for each JVM on the Cryostat web console. Storing credentials ensures that your automated rule starts, because Cryostat maintains a connection with each target JVM. For more information, see Storing and managing JMX credentials (Using Cryostat to manage a JFR recording) . When your target JVMs use a JMX connection, Cryostat stores JMX credentials in a keyring database. In this database, JMX credentials are encrypted by a user-provided passphrase that Cryostat supplies with the PG_ENCRYPT_KEY environment variable. Note From Cryostat 3.0 onward, the passphrase is supplied through the PG_ENCRYPT_KEY environment variable in the Cryostat DB container. In releases, the passphrase was supplied through the CRYOSTAT_JMX_CREDENTIALS_DB_PASSWORD environment variable in the Cryostat container. When installing a Cryostat instance, you can specify an encryption key manually by using the spec.databaseOptions.secretName property in the Cryostat custom resource (CR). Otherwise, if you leave the spec.databaseOptions.secretName property blank, the Cryostat Operator generates a key automatically.

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Chapter 3. User Access settings in the Red Hat Hybrid Cloud Console User Access is the Red Hat implementation of role-based access control (RBAC). Your Organization Administrator uses User Access to configure what users can see and do on the Red Hat Hybrid Cloud Console (the console): Control user access by organizing roles instead of assigning permissions individually to users. Create groups that include roles and their corresponding permissions. Assign users to these groups, allowing them to inherit the permissions associated with their group's roles. All users on your account have access to most of the data in Insights for Red Hat Enterprise Linux. 3.1. Predefined User Access groups and roles To make groups and roles easier to manage, Red Hat provides two predefined groups and a set of predefined roles. 3.1.1. Predefined groups The Default access group contains all users in your organization. Many predefined roles are assigned to this group. It is automatically updated by Red Hat. Note If the Organization Administrator makes changes to the Default access group its name changes to Custom default access group and it is no longer updated by Red Hat. The Default admin access group contains only users who have Organization Administrator permissions. This group is automatically maintained and users and roles in this group cannot be changed. On the Hybrid Cloud Console navigate to Red Hat Hybrid Cloud Console > the Settings icon (⚙) > Identity & Access Management > User Access > Groups to see the current groups in your account. This view is limited to the Organization Administrator. 3.1.2. Predefined roles assigned to groups The Default access group contains many of the predefined roles. Because all users in your organization are members of the Default access group, they inherit all permissions assigned to that group. The Default admin access group includes many (but not all) predefined roles that provide update and delete permissions. The roles in this group usually include administrator in their name. On the Hybrid Cloud Console navigate to Red Hat Hybrid Cloud Console > the Settings icon (⚙) > Identity & Access Management > User Access > Roles to see the current roles in your account. You can see how many groups each role is assigned to. This view is limited to the Organization Administrator. 3.2. Access permissions The Prerequisites for each procedure list which predefined role provides the permissions you must have. As a user, you can navigate to Red Hat Hybrid Cloud Console > the Settings icon (⚙) > My User Access to view the roles and application permissions currently inherited by you. If you try to access Insights for Red Hat Enterprise Linux features and see a message that you do not have permission to perform this action, you must obtain additional permissions. The Organization Administrator or the User Access administrator for your organization configures those permissions. Additional resources For more information about user access and permissions, see User Access Configuration Guide for Role-based Access Control (RBAC) with FedRAMP .

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Chapter 8. Red Hat Software Collections Red Hat Software Collections is a Red Hat content set that provides a set of dynamic programming languages, database servers, and related packages that you can install and use on all supported releases of Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7 on AMD64 and Intel 64 architectures. Red Hat Developer Toolset is included as a separate Software Collection. Red Hat Developer Toolset is designed for developers working on the Red Hat Enterprise Linux platform. It provides current versions of the GNU Compiler Collection, GNU Debugger, and other development, debugging, and performance monitoring tools. Since Red Hat Software Collections 2.3, the Eclipse development platform is provided as a separate Software Collection. Dynamic languages, database servers, and other tools distributed with Red Hat Software Collections do not replace the default system tools provided with Red Hat Enterprise Linux, nor are they used in preference to these tools. Red Hat Software Collections uses an alternative packaging mechanism based on the scl utility to provide a parallel set of packages. This set enables optional use of alternative package versions on Red Hat Enterprise Linux. By using the scl utility, users can choose which package version they want to run at any time. Important Red Hat Software Collections has a shorter life cycle and support term than Red Hat Enterprise Linux. For more information, see the Red Hat Software Collections Product Life Cycle . See the Red Hat Software Collections documentation for the components included in the set, system requirements, known problems, usage, and specifics of individual Software Collections. See the Red Hat Developer Toolset documentation for more information about the components included in this Software Collection, installation, usage, known problems, and more.

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3.5. Configuring FTP File Transport Protocol (FTP) is an old and complex multi-port protocol that presents a distinct set of challenges to an LVS environment. To understand the nature of these challenges, you must first understand some key things about how FTP works. 3.5.1. How FTP Works With most other server client relationships, the client machine opens up a connection to the server on a particular port and the server then responds to the client on that port. When an FTP client connects to an FTP server it opens a connection to the FTP control port 21. Then the client tells the FTP server whether to establish an active or passive connection. The type of connection chosen by the client determines how the server responds and on what ports transactions will occur. The two types of data connections are: Active Connections When an active connection is established, the server opens a data connection to the client from port 20 to a high range port on the client machine. All data from the server is then passed over this connection. Passive Connections When a passive connection is established, the client asks the FTP server to establish a passive connection port, which can be on any port higher than 10,000. The server then binds to this high-numbered port for this particular session and relays that port number back to the client. The client then opens the newly bound port for the data connection. Each data request the client makes results in a separate data connection. Most modern FTP clients attempt to establish a passive connection when requesting data from servers. Note The client determines the type of connection, not the server. This means to effectively cluster FTP, you must configure the LVS routers to handle both active and passive connections. The FTP client/server relationship can potentially open a large number of ports that the Piranha Configuration Tool and IPVS do not know about.

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Chapter 2. Overview .NET is a general purpose, modular, cross-platform, and open source implementation of .NET that features automatic memory management and modern programming languages. It allows users to build high-quality applications efficiently. .NET 8.0 is available on RHEL 8.9 and later, RHEL 9.3 and later. .NET 8.0 is a Long Term Support (LTS) release. LTS releases releases reach End of Support after around 3 years. For more information, see the Life Cycle and Support Policies for the .NET Program . .NET offers: The ability to follow a microservices-based approach, where some components are built with .NET and others with Java or JavaScript, but all can run on a common, supported platform in RHEL. The capacity to more easily develop new .NET workloads on Microsoft Windows. You can deploy and run on either RHEL or Windows Server. A heterogeneous data center, where the underlying infrastructure is capable of running .NET applications without having to rely solely on Windows Server.

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13.2. Rename A Model To rename a model in your workspace: Select a model in the Model Explorer view. Right-click select the Refactor > Rename action. Figure 13.1. Refactor Rename Action In Model Explorer Specify unique model name in the Rename Resource dialog. Click OK . Figure 13.2. Rename Resource Dialog Note Renaming a model that is a dependency to another model will automatically change the model imports for those models. If source model CustomerSource is renamed to OldCustomerSource, for instance, the import statement for the view model CustomerAccounts which imports CustomerSource will be changed to reflect the new name.

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Part I. About the subscriptions service The subscriptions service in the Hybrid Cloud Console provides a visual representation of the subscription experience across your hybrid infrastructure in a dashboard-based application. The subscriptions service is intended to simplify how you interact with your subscriptions, providing both a historical look-back at your subscription usage and an ability to make informed, forward-facing decisions based on that usage and your remaining subscription capacity. Learn more To learn more about the subscriptions service, see the following information: What is the subscriptions service? To learn more about the benefits that the subscriptions service offers, see the following information: What are the benefits of the subscriptions service? To learn more about the current capabilities of the subscriptions service, see the following information: What does the subscriptions service track?

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8.88. libdrm 8.88.1. RHBA-2013:1551 - libdrm bug fix and enhancement update Updated libdrm packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 6. The Direct Rendering Manager runtime library (libdrm) provides a user-space interface library for direct rendering clients. Note The libdrm packages have been upgraded to upstream version 2.4.45, which provides a number of bug fixes and enhancements over the version. (BZ# 914774 ) Users of libdrm are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.

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Chapter 6. LVM Troubleshooting This chapter provides instructions for troubleshooting a variety of LVM issues. 6.1. Troubleshooting Diagnostics If a command is not working as expected, you can gather diagnostics in the following ways: Use the -v , -vv , -vvv , or -vvvv argument of any command for increasingly verbose levels of output. If the problem is related to the logical volume activation, set activation = 1 in the log section of the configuration file and run the command with the -vvvv argument. After you have finished examining this output be sure to reset this parameter to 0, to avoid possible problems with the machine locking during low memory situations. Run the lvmdump command, which provides an information dump for diagnostic purposes. For information, see the lvmdump (8) man page. Execute the lvs -v , pvs -a , or dmsetup info -c command for additional system information. Examine the last backup of the metadata in the /etc/lvm/backup file and archived versions in the /etc/lvm/archive file. Check the current configuration information by running the lvmconfig command. Check the .cache file in the /etc/lvm directory for a record of which devices have physical volumes on them.

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Chapter 1. Managing the publication process of internal collections in Automation Hub Use automation hub to manage and publish content collections developed within your organization. You can upload and group collections in namespaces. They need administrative approval to appear in the Published content repository. After you publish a collection, your users can access and download it for use. Additionally, you can reject submitted collections that do not meet organizational certification criteria. 1.1. About Approval You can manage uploaded collections in automation hub using the Approval feature located in the left navigation. Approval Dashboard By default, the Approval dashboard lists all collections with Needs Review status. You can check these for inclusion in your Published repository. Viewing collection details You can view more information about the collection by clicking the Version number. Filtering collections Filter collections by Namespace , Collection Name or Repository , to locate content and update its status. 1.2. Approving collections for internal publication You can approve collections uploaded to individual namespaces for internal publication and use. All collections awaiting review are located under the Approval tab in the Staging repository. Collections requiring approval have the status Needs review . Click the Version to view the contents of the collection. Prerequisites You have Modify Ansible repo content permissions. Procedure From the sidebar, navigate to Approval . Select a collection to review. Click Certify to approve the collection. Approved collections are moved to the Published repository where users can view and download them for use. 1.3. Rejecting collections uploaded for review You can reject collections uploaded to individual namespaces. All collections awaiting review are located under the Approval tab in the Staging repository. Collections requiring approval have the status Needs review . Click the Version to view the contents of the collection. Prerequisites You have Modify Ansible repo content permissions. Procedure From the sidebar, navigate to Approval . Locate the collection to review. Click Reject to decline the collection. Collections you decline for publication are moved to the Rejected repository.

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3.2. Starting luci and ricci To administer Red Hat Clusters with Conga , install and run luci and ricci as follows: At each node to be administered by Conga , install the ricci agent. For example: At each node to be administered by Conga , start ricci . For example: Select a computer to host luci and install the luci software on that computer. For example: Note Typically, a computer in a server cage or a data center hosts luci ; however, a cluster computer can host luci . At the computer running luci , initialize the luci server using the luci_admin init command. For example: Start luci using service luci restart . For example: At a Web browser, place the URL of the luci server into the URL address box and click Go (or the equivalent). The URL syntax for the luci server is https:// luci_server_hostname :8084 . The first time you access luci , two SSL certificate dialog boxes are displayed. Upon acknowledging the dialog boxes, your Web browser displays the luci login page.

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up2date -i ricci
service ricci start Starting ricci: [ OK ]
up2date -i luci
luci_admin init Initializing the Luci server Creating the 'admin' user Enter password: <Type password and press ENTER.> Confirm password: <Re-type password and press ENTER.> Please wait The admin password has been successfully set. Generating SSL certificates Luci server has been successfully initialized Restart the Luci server for changes to take effect eg. service luci restart
service luci restart Shutting down luci: [ OK ] Starting luci: generating https SSL certificates... done [ OK ] Please, point your web browser to https://nano-01:8084 to access luci