mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 6. Configure Host Names 6.1. Understanding Host Names There are three classes of hostname : static, pretty, and transient. The " static " host name is the traditional hostname , which can be chosen by the user, and is stored in the /etc/hostname file. The " transient " hostname is a dynamic host name maintained by the kernel. It is initialized to the static host name by default, whose value defaults to " localhost " . It can be changed by DHCP or mDNS at runtime. The " pretty " hostname is a free-form UTF8 host name for presentation to the user. Note A host name can be a free-form string up to 64 characters in length. However, Red Hat recommends that both static and transient names match the fully-qualified domain name ( FQDN ) used for the machine in DNS , such as host.example.com . It is also recommended that the static and transient names consists only of 7 bit ASCII lower-case characters, no spaces or dots, and limits itself to the format allowed for DNS domain name labels, even though this is not a strict requirement. Older specifications do not permit the underscore, and so their use is not recommended. The hostnamectl tool will enforce the following: Static and transient host names to consist of a-z , A-Z , 0-9 , " - " , " _ " and " . " only, to not begin or end in a dot, and to not have two dots immediately following each other. The size limit of 64 characters is enforced. 6.1.1. Recommended Naming Practices The Internet Corporation for Assigned Names and Numbers (ICANN) sometimes adds previously unregistered Top-Level Domains (such as .yourcompany ) to the public register. Therefore, Red Hat strongly recommends that you do not use a domain name that is not delegated to you, even on a private network, as this can result in a domain name that resolves differently depending on network configuration. As a result, network resources can become unavailable. Using domain names that are not delegated to you also makes DNSSEC more difficult to deploy and maintain, as domain name collisions require manual configuration to enable DNSSEC validation. See the ICANN FAQ on domain name collision for more information on this issue.

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3.6. Do You Have Enough Disk Space? Nearly every modern-day operating system (OS) uses disk partitions , and Red Hat Enterprise Linux is no exception. When you install Red Hat Enterprise Linux, you may have to work with disk partitions. If you have not worked with disk partitions before (or need a quick review of the basic concepts), refer to Appendix A, An Introduction to Disk Partitions before proceeding. The disk space used by Red Hat Enterprise Linux must be separate from the disk space used by other OSes you may have installed on your system, such as Windows, OS/2, or even a different version of Linux. For x86, AMD64, and Intel 64 systems, at least two partitions ( / and swap ) must be dedicated to Red Hat Enterprise Linux. Before you start the installation process, you must have enough unpartitioned [1] disk space for the installation of Red Hat Enterprise Linux, or have one or more partitions that may be deleted, thereby freeing up enough disk space to install Red Hat Enterprise Linux. To gain a better sense of how much space you really need, refer to the recommended partitioning sizes discussed in Section 9.15.5, "Recommended Partitioning Scheme" . If you are not sure that you meet these conditions, or if you want to know how to create free disk space for your Red Hat Enterprise Linux installation, refer to Appendix A, An Introduction to Disk Partitions . [1] Unpartitioned disk space means that available disk space on the hard drives you are installing to has not been divided into sections for data. When you partition a disk, each partition behaves like a separate disk drive.

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8.55. glusterfs 8.55.1. RHBA-2013:1641 - glusterfs bug fix and enhancement update Updated glusterfs packages that fix several bugs and add one enhancement are now available for Red Hat Enterprise Linux 6. Red Hat Storage is software only, scale-out storage that provides flexible and affordable unstructured data storage for the enterprise. GlusterFS, a key building block of Red Hat Storage, is based on a stackable user-space design and can deliver exceptional performance for diverse workloads. GlusterFS aggregates various storage servers over network interconnects into one large, parallel network file system. Bug Fixes BZ# 998778 Previously, the "errno" value was not set correctly during an API failure. Consequently, applications using API could behave unpredictably. With this update, the value is set properly during API failures and the applications work as expected. BZ# 998832 Previously, the glusterfs-api library handled all signals that were sent to applications using glusterfs-api. As a consequence, glusterfs-api interpreted incorrectly all the the signals that were not used by this library. With this update, glusterfs-api no longer handles the signals that it does not use so that such signals are now interpreted properly. BZ# 1017014 Previously, the glfs_fini() function did not return NULL, even if the libgfapi library successfully cleaned up all resources. Consequently, an attempt to use the "qemu-img create" command, which used libgfapi, failed. The underlying source code has been modified so that the function returns NULL when the libgfapi cleanup is successful, and the command now works as expected. Enhancement BZ# 916645 Native Support for GlusterFS in QEMU has been included to glusterfs packages. This support allows native access to GlusterFS volumes using the libgfapi library instead of through a locally mounted FUSE file system. This native approach offers considerable performance improvements. Users of glusterfs are advised to upgrade to these updated packages, which fix these bugs and add this enhancement.

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function::user_string2_utf32 Name function::user_string2_utf32 - Retrieves UTF-32 string from user memory with alternative error string Synopsis Arguments addr The user address to retrieve the string from err_msg The error message to return when data isn't available Description This function returns a null terminated UTF-8 string converted from the UTF-32 string at a given user memory address. Reports the given error message on string copy fault or conversion error.

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user_string2_utf32:string(addr:long,err_msg:string)
Appendix A. Fuse Console Configuration Properties By default, the Fuse Console configuration is defined in the hawtconfig.json file. You can customize the Fuse Console configuration information, such as title, logo, and login page information. Table A.1, "Fuse Console Configuration Properties" provides a description of the properties and lists whether or not each property requires a value. Table A.1. Fuse Console Configuration Properties Section Property Name Default Value Description Required? About Title Red Hat Fuse Management Console The title that shows on the About page of the Fuse Console. Required productInfo Empty value Product information that shows on the About page of the Fuse Console. Optional additionalInfo Empty value Any additional information that shows on the About page of the Fuse Console. Optional

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Chapter 7. Viewing the status of the QuayRegistry object Lifecycle observability for a given Red Hat Quay deployment is reported in the status section of the corresponding QuayRegistry object. The Red Hat Quay Operator constantly updates this section, and this should be the first place to look for any problems or state changes in Red Hat Quay or its managed dependencies. 7.1. Viewing the registry endpoint Once Red Hat Quay is ready to be used, the status.registryEndpoint field will be populated with the publicly available hostname of the registry. 7.2. Viewing the config editor endpoint Access Red Hat Quay's UI-based config editor using status.configEditorEndpoint . 7.3. Viewing the config editor credentials secret The username and password for the config editor UI will be stored in a Secret in the same namespace as the QuayRegistry referenced by status.configEditorCredentialsSecret . 7.4. Viewing the version of Red Hat Quay in use The current version of Red Hat Quay that is running will be reported in status.currentVersion . 7.5. Viewing the conditions of your Red Hat Quay deployment Certain conditions will be reported in status.conditions .

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9.16. Write Changes to Disk The installer prompts you to confirm the partitioning options that you selected. Click Write changes to disk to allow the installer to partition your hard drive and install Red Hat Enterprise Linux. Figure 9.47. Writing storage configuration to disk If you are certain that you want to proceed, click Write changes to disk . Warning Up to this point in the installation process, the installer has made no lasting changes to your computer. When you click Write changes to disk , the installer will allocate space on your hard drive and start to transfer Red Hat Enterprise Linux into this space. Depending on the partitioning option that you chose, this process might include erasing data that already exists on your computer. To revise any of the choices that you made up to this point, click Go back . To cancel installation completely, switch off your computer. To switch off most computers at this stage, press the power button and hold it down for a few seconds. After you click Write changes to disk , allow the installation process to complete. If the process is interrupted (for example, by you switching off or resetting the computer, or by a power outage) you will probably not be able to use your computer until you restart and complete the Red Hat Enterprise Linux installation process, or install a different operating system.

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10.3. Removing a Guest Virtual Machine Entry If the guest virtual machine is running, unregister the system, by running the following command in a terminal window as root on the guest: If the system has been deleted, however, the virtual service cannot tell whether the service is deleted or paused. In that case, you must manually remove the system from the server side, using the following steps: Login to the Subscription Manager The Subscription Manager is located on the Red Hat Customer Portal . Login to the Customer Portal using your user name and password, by clicking the login icon at the top of the screen. Click the Subscriptions tab Click the Subscriptions tab. Click the Systems link Scroll down the page and click the Systems link. Delete the system To delete the system profile, locate the specified system's profile in the table, select the check box beside its name and click Delete .

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subscription-manager unregister
20.3. Event Sequence of an SSH Connection The following series of events help protect the integrity of SSH communication between two hosts. A cryptographic handshake is made so that the client can verify that it is communicating with the correct server. The transport layer of the connection between the client and remote host is encrypted using a symmetric cipher. The client authenticates itself to the server. The remote client interacts with the remote host over the encrypted connection. 20.3.1. Transport Layer The primary role of the transport layer is to facilitate safe and secure communication between the two hosts at the time of authentication and during subsequent communication. The transport layer accomplishes this by handling the encryption and decryption of data, and by providing integrity protection of data packets as they are sent and received. The transport layer also provides compression, speeding the transfer of information. Once an SSH client contacts a server, key information is exchanged so that the two systems can correctly construct the transport layer. The following steps occur during this exchange: Keys are exchanged The public key encryption algorithm is determined The symmetric encryption algorithm is determined The message authentication algorithm is determined The hash algorithm is determined During the key exchange, the server identifies itself to the client with a unique host key . If the client has never communicated with this particular server before, the server's host key is unknown to the client and it does not connect. OpenSSH gets around this problem by accepting the server's host key after the user is notified and verifies the acceptance of the new host key. In subsequent connections, the server's host key is checked against the saved version on the client, providing confidence that the client is indeed communicating with the intended server. If, in the future, the host key no longer matches, the user must remove the client's saved version before a connection can occur. Warning It is possible for an attacker to masquerade as an SSH server during the initial contact since the local system does not know the difference between the intended server and a false one set up by an attacker. To help prevent this, verify the integrity of a new SSH server by contacting the server administrator before connecting for the first time or in the event of a host key mismatch. SSH is designed to work with almost any kind of public key algorithm or encoding format. After an initial key exchange creates a hash value used for exchanges and a shared secret value, the two systems immediately begin calculating new keys and algorithms to protect authentication and future data sent over the connection. After a certain amount of data has been transmitted using a given key and algorithm (the exact amount depends on the SSH implementation), another key exchange occurs, generating another set of hash values and a new shared secret value. Even if an attacker is able to determine the hash and shared secret value, this information is only useful for a limited period of time.

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34.3. Additional Resources To learn more about configuring automated tasks, refer to the following resources. 34.3.1. Installed Documentation cron man page - overview of cron. crontab man pages in sections 1 and 5 - The man page in section 1 contains an overview of the crontab file. The man page in section 5 contains the format for the file and some example entries. /usr/share/doc/at- <version> /timespec contains more detailed information about the times that can be specified for cron jobs. at man page - description of at and batch and their command line options.

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Appendix A. Revision History Revision History Revision 3.8-7 Wed Dec 20 2023 Lenka Spackova Fixed broken links and anchors. Revision 3.8-6 Mon Jul 03 2023 Lenka Spackova The rh-mariadb103 Software Collection is EOL. Revision 3.8-5 Tue May 23 2023 Lenka Spackova Added information about Red Hat Developer Toolset 12.1. Revision 3.8-4 Tue Nov 22 2022 Lenka Spackova Added information about Red Hat Developer Toolset 12.0. Revision 3.8-3 Fri Nov 18 2022 Lenka Spackova Updated retired components. Updated component versions available with asynchronous updates. Revision 3.8-2 Thu Sep 29 2022 Lenka Spackova Added Section 1.3.7, "Changes in Apache httpd (asynchronous update)" . Revision 3.8-1 Mon Nov 15 2021 Lenka Spackova Release of Red Hat Software Collections 3.8 Release Notes. Revision 3.8-0 Mon Oct 11 2021 Lenka Spackova Release of Red Hat Software Collections 3.8 Beta Release Notes.

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Chapter 4. Virtualization Restrictions This chapter covers additional support and product restrictions of the virtualization packages in Red Hat Enterprise Linux 6. 4.1. KVM Restrictions The following restrictions apply to the KVM hypervisor: Maximum vCPUs per guest The maximum amount of virtual CPUs that is supported per guest varies depending on which minor version of Red Hat Enterprise Linux 6 you are using as a host machine. The release of 6.0 introduced a maximum of 64, while 6.3 introduced a maximum of 160. As of version 6.7, a maximum of 240 virtual CPUs per guest is supported. Constant TSC bit Systems without a Constant Time Stamp Counter require additional configuration. Refer to Chapter 14, KVM Guest Timing Management for details on determining whether you have a Constant Time Stamp Counter and configuration steps for fixing any related issues. Virtualized SCSI devices SCSI emulation is not supported with KVM in Red Hat Enterprise Linux. Virtualized IDE devices KVM is limited to a maximum of four virtualized (emulated) IDE devices per guest virtual machine. Migration restrictions Device assignment refers to physical devices that have been exposed to a virtual machine, for the exclusive use of that virtual machine. Because device assignment uses hardware on the specific host where the virtual machine runs, migration and save/restore are not supported when device assignment is in use. If the guest operating system supports hot plugging, assigned devices can be removed prior to the migration or save/restore operation to enable this feature. Live migration is only possible between hosts with the same CPU type (that is, Intel to Intel or AMD to AMD only). For live migration, both hosts must have the same value set for the No eXecution (NX) bit, either on or off . For migration to work, cache=none must be specified for all block devices opened in write mode. Warning Failing to include the cache=none option can result in disk corruption. Storage restrictions There are risks associated with giving guest virtual machines write access to entire disks or block devices (such as /dev/sdb ). If a guest virtual machine has access to an entire block device, it can share any volume label or partition table with the host machine. If bugs exist in the host system's partition recognition code, this can create a security risk. Avoid this risk by configuring the host machine to ignore devices assigned to a guest virtual machine. Warning Failing to adhere to storage restrictions can result in risks to security. Core dumping restrictions Core dumping uses the same infrastructure as migration and requires more device knowledge and control than device assignement can provide. Therefore, core dumping is not supported when device assignment is in use.

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Chapter 5. Installing the Virtualization Packages Before you can use virtualization, the virtualization packages must be installed on your computer. Virtualization packages can be installed either during the host installation sequence or after host installation using Subscription Manager. The KVM hypervisor uses the default Red Hat Enterprise Linux kernel with the kvm kernel module. 5.1. Configuring a Virtualization Host Installation This section covers installing virtualization tools and virtualization packages as part of a fresh Red Hat Enterprise Linux installation. Note The Red Hat Enterprise Linux Installation Guide covers installing Red Hat Enterprise Linux in detail. Procedure 5.1. Installing the virtualization package group Launch the Red Hat Enterprise Linux 6 installation program Start an interactive Red Hat Enterprise Linux 6 installation from the Red Hat Enterprise Linux Installation CD-ROM, DVD or PXE. Continue installation up to package selection Complete the other steps up to the package selection step. Figure 5.1. The Red Hat Enterprise Linux package selection screen Select the Virtualization Host server role to install a platform for guest virtual machines. Alternatively, ensure that the Customize Now radio button is selected before proceeding, to specify individual packages. Select the Virtualization package group This selects the qemu-kvm emulator, virt-manager , libvirt and virt-viewer for installation. Figure 5.2. The Red Hat Enterprise Linux package selection screen Note If you wish to create virtual machines in a graphical user interface ( virt-manager ) later, you should also select the General Purpose Desktop package group. Customize the packages (if required) Customize the Virtualization group if you require other virtualization packages. Figure 5.3. The Red Hat Enterprise Linux package selection screen Click on the Close button, then the button to continue the installation. When the installation is complete, reboot the system. Important You require a valid virtualization entitlement to receive updates for the virtualization packages. Installing KVM Packages with Kickstart Files Kickstart files allow for large, automated installations without a user manually installing each individual host system. This section describes how to create and use a Kickstart file to install Red Hat Enterprise Linux with the Virtualization packages. In the %packages section of your Kickstart file, append the following package groups: For more information about Kickstart files, refer to the Red Hat Enterprise Linux Installation Guide .

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@virtualization @virtualization-client @virtualization-platform @virtualization-tools
Chapter 61. System and Subscription Management Red Hat Satellite 5.8 availability of RHEL 7.6 EUS, AUS, TUS, and E4S streams delayed Red Hat Satellite 5 content ISOs are made available on a monthly cadence. Based on this cadence, content ISOs are not available through Red Hat Satellite 5.8 for the following RHEL 7.6 streams at the time of the RHEL 7.6 general availability: Extended Update Support (EUS) Advanced Update Support (AUS) Telco Extended Update Support (TUS) Update Services for SAP Solutions (E4S) The expected delay is two to four weeks. Note that Red Hat Satellite 6 instances are unaffected. See https://access.redhat.com/solutions/3621151 for more details. (BZ#1635135)

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1.3. Security Threats To plan and implement a good security strategy, first be aware of some of the issues which determined, motivated attackers exploit to compromise systems. 1.3.1. Threats to Network Security Bad practices when configuring the following aspects of a network can increase the risk of attack. 1.3.1.1. Insecure Architectures A misconfigured network is a primary entry point for unauthorized users. Leaving a trust-based, open local network vulnerable to the highly-insecure Internet is much like leaving a door ajar in a crime-ridden neighborhood - nothing may happen for an arbitrary amount of time, but eventually someone exploits the opportunity. 1.3.1.1.1. Broadcast Networks System administrators often fail to realize the importance of networking hardware in their security schemes. Simple hardware such as hubs and routers rely on the broadcast or non-switched principle; that is, whenever a node transmits data across the network to a recipient node, the hub or router sends a broadcast of the data packets until the recipient node receives and processes the data. This method is the most vulnerable to address resolution protocol ( ARP ) or media access control ( MAC ) address spoofing by both outside intruders and unauthorized users on local hosts. 1.3.1.1.2. Centralized Servers Another potential networking pitfall is the use of centralized computing. A common cost-cutting measure for many businesses is to consolidate all services to a single powerful machine. This can be convenient as it is easier to manage and costs considerably less than multiple-server configurations. However, a centralized server introduces a single point of failure on the network. If the central server is compromised, it may render the network completely useless or worse, prone to data manipulation or theft. In these situations, a central server becomes an open door which allows access to the entire network.

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probe::nfs.fop.sendfile Name probe::nfs.fop.sendfile - NFS client send file operation Synopsis nfs.fop.sendfile Values cache_valid cache related bit mask flag ppos current position of file count read bytes dev device identifier attrtimeo how long the cached information is assumed to be valid. We need to revalidate the cached attrs for this inode if jiffies - read_cache_jiffies > attrtimeo. ino inode number cache_time when we started read-caching this inode

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