mtpti5iD/redhat-docs_dataset huggingface dataset:
Appendix A. Using LVS with Red Hat Cluster You can use LVS routers with a Red Hat Cluster to deploy a high-availability e-commerce site that provides load balancing, data integrity, and application availability. The configuration in Figure A.1, "LVS with a Red Hat Cluster" represents an e-commerce site used for online merchandise ordering through a URL. Client requests to the URL pass through the firewall to the active LVS load-balancing router, which then forwards the requests to one of the Web servers. The Red Hat Cluster nodes serve dynamic data to the Web servers, which forward the data to the requesting client. Figure A.1. LVS with a Red Hat Cluster Serving dynamic Web content with LVS requires a three-tier configuration (as shown in Figure A.1, "LVS with a Red Hat Cluster" ). This combination of LVS and Red Hat Cluster allows for the configuration of a high-integrity, no-single-point-of-failure e-commerce site. The Red Hat Cluster can run a high-availability instance of a database or a set of databases that are network-accessible to the Web servers. A three-tier configuration is required to provide dynamic content. While a two-tier LVS configuration is suitable if the Web servers serve only static Web content (consisting of small amounts of infrequently changing data), a two-tier configuration is not suitable if the Web servers serve dynamic content. Dynamic content could include product inventory, purchase orders, or customer databases, which must be consistent on all the Web servers to ensure that customers have access to up-to-date and accurate information. Each tier provides the following functions: First tier - LVS routers performing load-balancing to distribute Web requests. Second tier - A set of Web servers to serve the requests. Third tier - A Red Hat Cluster to serve data to the Web servers. In an LVS configuration like the one in Figure A.1, "LVS with a Red Hat Cluster" , client systems issue requests on the World Wide Web. For security reasons, these requests enter a Web site through a firewall, which can be a Linux system serving in that capacity or a dedicated firewall device. For redundancy, you can configure firewall devices in a failover configuration. Behind the firewall are LVS load-balancing routers, which can be configured in an active-standby mode. The active load-balancing router forwards the requests to the set of Web servers. Each Web server can independently process an HTTP request from a client and send the response back to the client. LVS enables you to expand a Web site's capacity by adding Web servers behind the LVS routers; the LVS routers perform load balancing across a wider set of Web servers. In addition, if a Web server fails, it can be removed; LVS continues to perform load balancing across a smaller set of Web servers.

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12.7.3. Related Books DNS and BIND by Paul Albitz and Cricket Liu; O'Reilly &Associates - A popular reference that explains both common and esoteric BIND configuration options, as well as providing strategies for securing a DNS server. The Concise Guide to DNS and BIND by Nicolai Langfeldt; Que - Looks at the connection between multiple network services and BIND, with an emphasis on task-oriented, technical topics.

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Chapter 63. Storage The kexec -e command might cause storage errors with advanced storage controllers When using the kexec utility with the -e option, the system does not go through the standard Linux shutdown sequence before booting the kernel. This might cause problems for systems employing advanced storage controllers, such as the Qlogic QMH2672 Fibre Channel adapter, because these controllers rely on the shutdown sequence to assure the storage has settled at the time of a reboot. When invoking the kexec -e command on such systems, storage related errors might occur as the kexec operation progresses, and the newly loaded kernel might fail to discover some or all attached storage. If you see similar symptoms on your system when attempting kexec -e , use kexec without the -e option instead. This has been observed to work reliably. (BZ#1303244) LVM does not support event-based autoactivation of incomplete volume groups If a volume group is not complete and physical volumes are missing, LVM does not support automatic LVM event-based activation of that volume group. This implies a setting of --activationmode complete whenever autoactivation takes place. For information on the --activationmode complete option and automatic activation, see the vgchange(8) and pvscan(8) man pages. Note that the event-driven autoactivation hooks are enabled when lvmetad is enabled with the global/use_lvmetad=1 setting in the /etc/lvm/lvm.conf configuration file. Also note that without autoactivation, there is a direct activation hook at the exact time during boot at which the volume groups are activated with only the physical volumes that are available at that time. Any physical volumes that appear later are not taken into account. This issue does not affect early boot in initramfs ( dracut ) nor does this affect direct activation from the command line using vgchange and lvchange calls, which default to degraded activation mode. (BZ# 1337220 )

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probe::netfilter.bridge.post_routing Name probe::netfilter.bridge.post_routing - - Called before a bridging packet hits the wire Synopsis netfilter.bridge.post_routing Values llcproto_stp Constant used to signify Bridge Spanning Tree Protocol packet pf Protocol family -- always " bridge " indev Address of net_device representing input device, 0 if unknown nf_drop Constant used to signify a 'drop' verdict br_msg Message age in 1/256 secs nf_queue Constant used to signify a 'queue' verdict br_mac Bridge MAC address br_fd Forward delay in 1/256 secs brhdr Address of bridge header br_htime Hello time in 1/256 secs br_bid Identity of bridge br_rmac Root bridge MAC address protocol Packet protocol br_prid Protocol identifier br_type BPDU type nf_stop Constant used to signify a 'stop' verdict br_max Max age in 1/256 secs br_rid Identity of root bridge br_flags BPDU flags outdev_name Name of network device packet will be routed to (if known) nf_accept Constant used to signify an 'accept' verdict indev_name Name of network device packet was received on (if known) br_poid Port identifier outdev Address of net_device representing output device, 0 if unknown nf_repeat Constant used to signify a 'repeat' verdict br_vid Protocol version identifier length The length of the packet buffer contents, in bytes nf_stolen Constant used to signify a 'stolen' verdict br_cost Total cost from transmitting bridge to root llcpdu Address of LLC Protocol Data Unit

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21.2. Files Related to SELinux The following sections describe SELinux configuration files and related file systems. 21.2.1. The /selinux/ Pseudo-File System The /selinux/ pseudo-file system contains commands that are most commonly used by the kernel subsystem. This type of file system is similar to the /proc/ pseudo-file system. In most cases, administrators and users do not need to manipulate this component compared to other SELinux files and directories. The following example shows sample contents of the /selinux/ directory: For example, running the cat command on the enforce file reveals either a 1 for enforcing mode or 0 for permissive mode.

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-rw-rw-rw- 1 root root 0 Sep 22 13:14 access dr-xr-xr-x 1 root root 0 Sep 22 13:14 booleans --w------- 1 root root 0 Sep 22 13:14 commit_pending_bools -rw-rw-rw- 1 root root 0 Sep 22 13:14 context -rw-rw-rw- 1 root root 0 Sep 22 13:14 create --w------- 1 root root 0 Sep 22 13:14 disable -rw-r--r-- 1 root root 0 Sep 22 13:14 enforce -rw------- 1 root root 0 Sep 22 13:14 load -r--r--r-- 1 root root 0 Sep 22 13:14 mls -r--r--r-- 1 root root 0 Sep 22 13:14 policyvers -rw-rw-rw- 1 root root 0 Sep 22 13:14 relabel -rw-rw-rw- 1 root root 0 Sep 22 13:14 user
7.192. PyQt4 7.192.1. RHBA-2012:1241 - PyQt4 bug fix update Updated PyQt4 packages that fix two bugs are now available for Red Hat Enterprise Linux 6. The PyQt4 packages contain python bindings for Qt4. Bug Fixes BZ# 757411 Prior to this update, the PyQt4 utility did not contain the deleteResource method of PyQt4.QtNetwork.QNetworkAccessManager. This update modifies the underlying code to include the missing qnetwork-deleteResource method. BZ# 821061 Prior to this update, the PyQt4 utility did not contain the QMenuBar.setCornerWidget method. This update modifies the underlying code to include the missing qmenubar-cornerWidget method. All users of PyQt4 are advised to upgrade to these updated packages, which fix these bugs.

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8.4. Buffer Manager Metrics Name Property Description Comment Disk Write Count ENGINE_STATISTIC.buffermgr-disk-write-count Disk write count for the buffer manager. Disk Read Count ENGINE_STATISTIC.buffermgr-disk-read-count Disk read count for the buffer manager. Cache Write Count ENGINE_STATISTIC.buffermgr-cache-write-count Cache write count for the buffer manager. Cache Read Count ENGINE_STATISTIC.buffermgr-cache-read-count Cache read count for the buffer manager. Disk Space Used (MB) ENGINE_STATISTIC.buffermgr-diskspace-used-mb Indicates amount of storage space currently used by buffer files Setup alert to warn when used buffer space is at an unacceptable level, based on the setting of max-buffer-space Total memory in use (KB) ENGINE_STATISTIC.total-memory-inuse-kb Estimate of the current memory usage in kilobytes. Total memory in use by active plans (KB) ENGINE_STATISTIC.total-memory-inuse-active-plans-kb Estimate of the current memory usage by active plans in kilobytes

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8.3. Fixing Problems The following sections help troubleshoot issues. They go over: checking Linux permissions, which are checked before SELinux rules; possible causes of SELinux denying access, but no denials being logged; manual pages for services, which contain information about labeling and Booleans; permissive domains, for allowing one process to run permissive, rather than the whole system; how to search for and view denial messages; analyzing denials; and creating custom policy modules with audit2allow . 8.3.1. Linux Permissions When access is denied, check standard Linux permissions. As mentioned in Chapter 2, Introduction , most operating systems use a Discretionary Access Control (DAC) system to control access, allowing users to control the permissions of files that they own. SELinux policy rules are checked after DAC rules. SELinux policy rules are not used if DAC rules deny access first. If access is denied and no SELinux denials are logged, use the ls -l command to view the standard Linux permissions: In this example, index.html is owned by the root user and group. The root user has read and write permissions ( -rw ), and members of the root group have read permissions ( -r- ). Everyone else has no access ( --- ). By default, such permissions do not allow httpd to read this file. To resolve this issue, use the chown command to change the owner and group. This command must be run as the Linux root user: This assumes the default configuration, in which httpd runs as the Linux apache user. If you run httpd with a different user, replace apache:apache with that user. Refer to the Fedora Documentation Project "Permissions" draft for information about managing Linux permissions.

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~]USD ls -l /var/www/html/index.html -rw-r----- 1 root root 0 2009-05-07 11:06 index.html
~]# chown apache:apache /var/www/html/index.html
Chapter 1. Red Hat build of OpenJDK applications in containers Red Hat build of OpenJDK images have default startup scripts that automatically detect application JAR files and launch Java. The script's behavior can be customized using environment variables. For more information, see /help.md in the container. The Java applications in the /deployments directory of the OpenJDK image are run when the image loads. Note Containers that contain Red Hat build of OpenJDK applications are not automatically updated with security updates. Ensure that you update these images at least once every three months. Application JAR files can be fat JARs or thin JARs. Fat JARs contain all of the application's dependencies. Thin JARs reference other JARs that contain some, or all, of the application's dependencies. Thin JARs are only supported if: They have a flat classpath. All dependencies are JARs that are in the /deployments directory.

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2.2.2.5. Syntax Changes Changes to the core Kickstart syntax are quite rare. However, there are two important syntax changes to be aware of: The %include option can now accept a URL as an argument, in addition to a file name. The %packages , %post , %pre and %traceback sections do not require an %end section. A deprecation warning will appear if %end sections are not included, but the script will continue to run.

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A.2. Configuring Shared Storage To set up the shared file system resource, perform the following tasks as root on one cluster system: On one cluster node, use the interactive parted utility to create a partition to use for the document root directory. Note that it is possible to create multiple document root directories on different disk partitions. Use the mkfs command to create an ext3 file system on the partition you created in the step. Specify the drive letter and the partition number. For example: Mount the file system that contains the document root directory. For example: Do not add this mount information to the /etc/fstab file because only the cluster software can mount and unmount file systems used in a service. Copy all the required files to the document root directory. If you have CGI files or other files that must be in different directories or in separate partitions, repeat these steps, as needed.

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mkfs -t ext3 /dev/sde3
mount /dev/sde3 /var/www/html
Appendix A. Revision History Revision History Revision 3.7-5 Wed Dec 20 2023 Lenka Spackova Fixed broken links and anchors. Revision 3.7-4 Fri Nov 12 2021 Lenka Spackova Updated Section 4.3, "Database Connectors" . Revision 3.7-3 Tue Aug 24 2021 Lenka Spackova Added two notes related to asynchronous changes in Python due to CVE fixes ( Section 1.6, "Other Notes" ). Extended Section 1.3.5, "Changes in Ruby" . Revision 3.7-2 Mon Jul 12 2021 Lenka Spackova Added a note about the .mysql_history file. Revision 3.7-1 Thu Jun 03 2021 Lenka Spackova Release of Red Hat Software Collections 3.7 Release Notes. Revision History Revision 3.7-0 Mon May 03 2021 Lenka Spackova Release of Red Hat Software Collections 3.7 Beta Release Notes.

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9.3.2. Software RAID Software RAID implements the various RAID levels in the kernel disk (block device) code. It offers the cheapest possible solution, as expensive disk controller cards or hot-swap chassis [2] are not required. Software RAID also works with cheaper IDE disks as well as SCSI disks. With today's fast CPUs, Software RAID performance can excel against Hardware RAID. The MD driver in the Linux kernel is an example of a RAID solution that is completely hardware independent. The performance of a software-based array is dependent on the server CPU performance and load. For information on configuring Software RAID during installation, refer to the Chapter 10, Software RAID Configuration . For those interested in learning more about what Software RAID has to offer, here are the most important features: Threaded rebuild process Kernel-based configuration Portability of arrays between Linux machines without reconstruction Backgrounded array reconstruction using idle system resources Hot-swappable drive support Automatic CPU detection to take advantage of certain CPU optimizations [2] A hot-swap chassis allows you to remove a hard drive without having to power-down your system.

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7.310. pcs 7.310.1. RHEA-2013:0655 - pcs bug fix update Updated pcs packages that fix one bug are now available for Red Hat Enterprise Linux 6. The pcs packages provide a command-line tool to configure and manage Pacemaker and Corosync tools. Bug Fix BZ# 915585 The "pcs config" command did not show resources configured as master and slave resources when the configuration of the Pacemaker cluster was reviewed. Consequently, users had to directly analyze the CIB to view the configured master and slave resources and their options. This update provides a patch to address this bug, so the "pcs config" command now shows all resources, including master and slave resources. Users of pcs are advised to upgrade to these updated packages, which fix this bug. 7.310.2. RHBA-2013:1492 - pcs bug fix and enhancement update Updated pcs package that fix several bugs and add various enhancements is now available for Red Hat Enterprise Linux 6. The pcs packages provide a command-line tool to configure and manage the Pacemaker and Corosync tools. Note The pcs package has been upgraded to upstream version 0.9.90, which provides a number of bug fixes and enhancements over the version. (BZ# 1003482 ) Users of pcs are advised to upgrade to this updated package, which fix these bugs and add these enhancements.

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5.217. numpy 5.217.1. RHBA-2012:0986 - numpy bug fix and enhancement update Updated numpy packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 6. The numpy packages provide NumPY. NumPY is an extension to the Python programming language, which adds support for large, multi-dimensional arrays and matrices, and a library of mathematical functions that operate on such arrays. The numpy packages have been upgraded to upstream version 1.4.1, which provides a number of bug fixes and enhancements over the version. BZ# 692959 This update introduces two important changes in NumPY's behavior: When operating on 0-d arrays, the numpy.max() function and other functions now no longer accept axis values other than 0, -1, and None, and NumPY now raises an error for other axis values. It is now no longer possible to specify an axis value greater than the MAX_DIMS value and NumPY now raises an error under these circumstances. Refer to the /usr/share/doc/numpy-1.4.1/1.4.0-notes.rst file for further details about the changes. Users of numpy are advised to upgrade to these updated numpy packages, which fix these bugs and add these enhancements.

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Chapter 2. Building and Securing Containers This chapter describes security concerns involving the building and distribution of Docker containers. Docker's Unsigned Binary Docker's official binary installation is not signed. The Dangers of Untrusted Content The process of installing RPMs involves two phases: (1) the retrieval phase, and (2) the istallation phase. This separation between retrieval and installation does not exist in the Docker workflow. There are a number of CVEs related to this issue. Docker images are stored as tars, and they can escape the docker daemon without your knowing it. docker pull is an active process - unlike RPMs, there is no separation between the retrieval phase of installation and the installation phase docker containers run as root - you should run Docker content that has originated only from trusted vendors

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Chapter 5. Ansible content migration If you are migrating from an ansible-core version to ansible-core 2.13, consider reviewing Ansible core Porting Guides to familiarize yourself with changes and updates between each version. When reviewing the Ansible core porting guides, ensure that you select the latest version of ansible-core or devel , which is located at the top left column of the guide. For a list of fully supported and certified Ansible Content Collections, see Ansible Automation hub on console.redhat.com . 5.1. Migrating your Ansible playbooks and roles to Core 2.13 When you are migrating from non collection-based content to collection-based content, you should use the Fully Qualified Collection Names (FQCN) in playbooks and roles to avoid unexpected behavior. Example playbook with FQCN: - name: get some info amazon.aws.ec2_vpc_net_info: region: "{{ec2_region}}" register: all_the_info delegate_to: localhost run_once: true If you are using ansible-core modules and are not calling a module from a different Collection, you should use the FQCN ansible.builtin.copy . Example module with FQCN: - name: copy file with owner and permissions ansible.builtin.copy: src: /srv/myfiles/foo.conf dest: /etc/foo.conf owner: foo group: foo mode: '0644'

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- name: get some info amazon.aws.ec2_vpc_net_info: region: "{{ec2_region}}" register: all_the_info delegate_to: localhost run_once: true
- name: copy file with owner and permissions ansible.builtin.copy: src: /srv/myfiles/foo.conf dest: /etc/foo.conf owner: foo group: foo mode: '0644'
Chapter 7. Known issues This section documents known issues found in this release of Red Hat Ceph Storage. 7.1. Ceph Object Gateway Use the yes-i-know flag to bootstrap the Red Hat Ceph Storage cluster 5.1 Users are warned against configuring multi-site in a Red Hat Ceph Storage cluster 5.1. To work around this issue, you must pass the yes-i-know flag during bootstrapping. Syntax Users are warned while upgrading to Red Hat Ceph Storage 5.1 Previously, buckets resharded in Red Hat Ceph Storage 5.0, might not have been understandable by a Red Hat Ceph Storage 5.1 Ceph Object Gateway daemon, due to which an upgrade warning or blocker was added to make sure all users upgrading to Red Hat Ceph Storage 5.1 are aware of the issue and can downgrade if they were previously using Red Hat Ceph Storage 5.1. As a workaround, run ceph config set mgr mgr/cephadm/yes_i_know true --force command to remove the warning or blocker and return all operations to normal. Users have to acknowledge that they are aware of the Ceph Object Gateway issue before they upgrade to Red Hat Ceph Storage 5.1. If the flag is not passed, you get an error message about the multi-site regression and the link to the knowledge base article on the issue. ( BZ#2111679 )

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sudo --image IMAGE_NAME bootstrap --mon-ip IP_ADDRESS --yes-i-know
Chapter 8. Performing maintenance and administration tasks on CUPS printers by using the web interface Printer administrators sometimes need to perform different tasks on a print server. For example: Maintenance tasks, such as temporary pausing a printer while a technician repairs a printer Administrative tasks, such as changing a printer's default settings You can perform these tasks by using the CUPS web interface. Prerequisites CUPS is configured . You have permissions in CUPS to manage printers . If you use CUPS as a print server, you configured TLS encryption to not send credentials in plain text over the network. The printer already exists in CUPS . Procedure Use a browser, and access https:// <hostname> :631/printers/ . You must connect to the web interface by using the HTTPS protocol. Otherwise, CUPS prevents you from authenticating in a later step for security reasons. Click on the name of the printer that you want to configure. Depending on whether you want to perform a maintenance or administration task, select the required action from the corresponding list: If you are not already authenticated, CUPS prompts for credentials of an administrative user. Enter the username and password of an authorized user. Perform the task.

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