mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 11. Compiler and Tools SystemTap Updated to Version 1.8 SystemTap is a tracing and probing tool that allows users to study and monitor the activities of the operating system (particularly, the kernel) in fine detail. It provides information similar to the output of tools like netstat , ps , top , and iostat ; however, SystemTap is designed to provide more filtering and analysis options for collected information. The systemtap package in Red Hat Enterprise Linux 6.4 has been upgraded to upstream version 1.8, which provides a number of bug fixes and enhancements: The @var syntax is now an alternative language syntax for accessing DWARF variables in uprobe and kprobe handlers (process, kernel, module). SystemTap now mangles local variables to avoid collisions with C headers included by tapsets. The SystemTap compile-server and client now support IPv6 networks, for hosts listed in DNS or mDNS. The SystemTap runtime ( staprun ) now accepts a -T timeout option to allow less frequent wake-ups to poll for low-throughput output from scripts. The SystemTap script translator driver ( stap ) now provides the following resource limit options: SystemTap modules are now smaller and compile faster. The modules' debuginfo is now suppressed by default. Bug CVE-2012-0875 (kernel panic when processing malformed DWARF unwind data) is now fixed. The lscpu and chcpu Utilities The lscpu utility, which displays detailed information about the available CPUs has been updated to include numerous new features. Also, a new utility, chcpu , has been added, which allows you to change the CPU state (online/offline, standby/active, and other states), disable and enable CPUs, and configure specified CPUs. For more information about these utilities, refer to the lscpu(1) and chcpu(8) man pages.

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--rlimit-as=NUM --rlimit-cpu=NUM --rlimit-nproc=NUM --rlimit-stack=NUM --rlimit-fsize=NUM
22.4. Installation Method Use the arrow keys on your keyboard to select an installation method (refer to Figure 22.4, "Installation Method" ). With your selected method highlighted, press the Tab key to move to the OK button and press the Enter key to confirm your choice. Figure 22.4. Installation Method 22.4.1. Installing from a DVD To install Red Hat Enterprise Linux from a DVD, place the DVD in your DVD drive and boot your system from the DVD as described in Section 20.1.4, " Using an FCP-attached SCSI DVD Drive" for z/VM or Section 20.2.5, "Using an FCP-attached SCSI DVD Drive" for LPAR. The installation program then probes your system and attempts to identify your DVD-ROM drive. It starts by looking for a SCSI DVD-ROM drive. Note To abort the installation process at this time, reboot your machine and then eject the boot media. You can safely cancel the installation at any point before the Write changes to disk screen. Refer to Section 23.16, "Write Changes to Disk" for more information. If the DVD drive is found and the driver loaded, the installer presents you with the option to perform a media check on the DVD. This takes some time, and you may opt to skip over this step. However, if you later encounter problems with the installer, you should reboot and perform the media check before calling for support. From the media check dialog, continue to the stage of the installation process (refer to Section 23.5, "Welcome to Red Hat Enterprise Linux" ).

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E.4. Troubleshooting GRUB In most cases, GRUB will be installed and configured during the initial installation process, unless you used a Kickstart file and specifically disabled this behavior. The installed system should therefore be prepared to boot into your desktop environment or a command line, depending on your package selection. However, in certain cases it is possible that the system's GRUB configuration becomes corrupted and the system will no longer be able to boot. This section describes how to fix such problems. When troubleshooting GRUB , keep in mind thatthe grub package does not automatically update the system boot loader when the package is updated using Yum or RPM . Therefore, updating the package will not automatically update the actual boot loader on your system. To work around this problem, use the grub-install command manually every time after the package is updated. See Section E.3, "Installing GRUB" for details about the command. Important GRUB cannot construct a software RAID. Therefore, the /boot directory must reside on a single, specific disk partition. The /boot directory cannot be striped across multiple disks, as in a level 0 RAID. To use a level 0 RAID on your system, place /boot on a separate partition outside the RAID. Similarly, because the /boot directory must reside on a single, specific disk partition, GRUB cannot boot the system if the disk holding that partition fails or is removed from the system. This is true even if the disk is mirrored in a level 1 RAID. The following Red Hat Knowledgebase article describes how to make the system bootable from another disk in the mirrored set: https://access.redhat.com/site/articles/7094 Note that these issues apply only to RAID that is implemented in software, where the individual disks that make up the array are still visible as individual disks on the system. These issues do not apply to hardware RAID where multiple disks are represented as a single device. The exact steps to fix a broken GRUB configuration will vary depending on what kind of problem there is. The GNU GRUB Manual offers a list of all possible error messages displayed by GRUB in different stages and their underlying causes. Use the manual for reference. Once you have determined the cause of the error, you can start fixing it. If you are encountering an error which only appears after you select an entry from the GRUB menu, then you can use the menu to fix the error temporarily, boot the system, and then fix the error permanently by running the grub-install command to reinstall the boot loader, or by editing the /boot/grub/grub.conf or /boot/efi/EFI/redhat/grub.conf with a plain text editor. For information about the configuration file structure, see Section E.8, "GRUB Menu Configuration File" . Note There are two identical files in the GRUB configuration directory: grub.conf and menu.lst . The grub.conf configuration file is loaded first; therefore you should make your changes there. The second file, menu.lst , will only be loaded if grub.conf is not found.

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20.4. Additional Resources The OpenSSH and OpenSSL projects are in constant development, and the most up-to-date information for them is available from their websites. The man pages for OpenSSH and OpenSSL tools are also good sources of detailed information. 20.4.1. Installed Documentation The ssh , scp , sftp , sshd , and ssh-keygen man pages - These man pages include information on how to use these commands as well as all the parameters that can be used with them.

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Chapter 14. Setting up additional trusted certificate authorities for builds Use the following sections to set up additional certificate authorities (CA) to be trusted by builds when pulling images from an image registry. The procedure requires a cluster administrator to create a ConfigMap and add additional CAs as keys in the ConfigMap . The ConfigMap must be created in the openshift-config namespace. domain is the key in the ConfigMap and value is the PEM-encoded certificate. Each CA must be associated with a domain. The domain format is hostname[..port] . The ConfigMap name must be set in the image.config.openshift.io/cluster cluster scoped configuration resource's spec.additionalTrustedCA field. 14.1. Adding certificate authorities to the cluster You can add certificate authorities (CA) to the cluster for use when pushing and pulling images with the following procedure. Prerequisites You must have access to the public certificates of the registry, usually a hostname/ca.crt file located in the /etc/docker/certs.d/ directory. Procedure Create a ConfigMap in the openshift-config namespace containing the trusted certificates for the registries that use self-signed certificates. For each CA file, ensure the key in the ConfigMap is the hostname of the registry in the hostname[..port] format: USD oc create configmap registry-cas -n openshift-config \ --from-file=myregistry.corp.com..5000=/etc/docker/certs.d/myregistry.corp.com:5000/ca.crt \ --from-file=otherregistry.com=/etc/docker/certs.d/otherregistry.com/ca.crt Update the cluster image configuration: USD oc patch image.config.openshift.io/cluster --patch '{"spec":{"additionalTrustedCA":{"name":"registry-cas"}}}' --type=merge 14.2. Additional resources Create a ConfigMap Secrets and ConfigMaps Configuring a custom PKI

Commands:
oc create configmap registry-cas -n openshift-config --from-file=myregistry.corp.com..5000=/etc/docker/certs.d/myregistry.corp.com:5000/ca.crt --from-file=otherregistry.com=/etc/docker/certs.d/otherregistry.com/ca.crt
oc patch image.config.openshift.io/cluster --patch '{"spec":{"additionalTrustedCA":{"name":"registry-cas"}}}' --type=merge
5.144. libdvdread 5.144.1. RHBA-2012:1247 - libdvdread bug fix update Updated libdvdread packages that fix one bug is now available for Red Hat Enterprise Linux 6. The libdvdread packages contain a simple foundation to read DVD video disks. This provides the functionality that is required to access many DVDs. Bug Fix BZ# 842016 Prior to this update, the dvd_stat_t structure was not public. As a consequence, source code that required such structures could not be compiled. This update makes the dvd_stat_t structure public, to allow compiling code with of this type. All users of libdvdread are advised to upgrade to these updated packages, which fix this bug.

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Chapter 22. Networking Mellanox SR-IOV Support Single Root I/O Virtualization (SR-IOV) is now supported as a Technology Preview in the Mellanox libmlx4 library and the following drivers: mlx_core mlx4_ib (InfiniBand protocol) mlx_en (Ethernet protocol) Package: kernel-2.6.32-642 QFQ queuing discipline In Red Hat Enterprise Linux 6, the tc utility has been updated to work with the Quick Fair Scheduler (QFQ) kernel features. Users can now take advantage of the new QFQ traffic queuing discipline from userspace. This feature is considered a Technology Preview. Package: kernel-2.6.32-642 vios-proxy, BZ# 721119 vios-proxy is a stream-socket proxy for providing connectivity between a client on a virtual guest and a server on a Hypervisor host. Communication occurs over virtio-serial links. Package: vios-proxy-0.2-1

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4.258. qpid-qmf 4.258.1. RHBA-2011:1671 - qpid-qmf bug fix and enhancement update Updated qpid-qmf packages that fix a bug and add various enhancements are now available for Red Hat Enterprise Linux 6. The qpid-qmf package provides an extensible management framework layered on Qpid messaging. The qpid-qmf package has been upgraded to upstream version 0.12, which provides a number of enhancements over the version. (BZ# 706990 ) Bug Fix BZ# 743657 Prior to this update, when "RequestContext._complete" was invoked, it would clear the Agent's context, but not the Agent's sequence manager. Consequently qmf console objects caused memory leaks. With this update the code has been corrected and the memory leak of object instances in the Python console no longer occurs. Enhancement BZ# 699499 The qmfv2 utility did not provide a way to determine via a pollable file descriptor if a new event was available. Consequently more processor intensive methods were used. With this update a new, optional, feature has been added, "qmf_fd". It is a file descriptor that is readable if, and only if, there is at least one qmf event to be processed. Users are advised to upgrade to these updated qpid-qmf packages, which fix this bug and adds this enhancement.

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probe::kprocess.exec Name probe::kprocess.exec - Attempt to exec to a new program Synopsis kprocess.exec Values filename The path to the new executable name Name of the system call ( " execve " ) (SystemTap v2.5+) args The arguments to pass to the new executable, including the 0th arg (SystemTap v2.5+) argstr A string containing the filename followed by the arguments to pass, excluding 0th arg (SystemTap v2.5+) Context The caller of exec. Description Fires whenever a process attempts to exec to a new program. Aliased to the syscall.execve probe in SystemTap v2.5+.

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8.4.4. Changing Default pacemaker_remote Options If you need to change the default port or authkey location for either Pacemaker or pacemaker_remote , there are environment variables you can set that affect both of those daemons. These environment variables can be enabled by placing them in the /etc/sysconfig/pacemaker file as follows. Note that when you change the default key location on a particular node (cluster node, guest node or remote node), it is sufficient to set PCMK_authkey_location on that node (and put the key in that location). It is not necessary that the location be the same on every node, although doing so makes administration easier. When changing the default port used by a particular guest node or remote node, the PCMK_remote_port variable must be set in that node's /etc/sysconfig/pacemaker file, and the cluster resource creating the guest node or remote node connection must also be configured with the same port number (using the remote-port metadata option for guest nodes, or the port option for remote nodes).

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#==#==# Pacemaker Remote Use a custom directory for finding the authkey. PCMK_authkey_location=/etc/pacemaker/authkey # Specify a custom port for Pacemaker Remote connections PCMK_remote_port=3121
2.5. Turning on Packet Forwarding In order for the LVS router to forward network packets properly to the real servers, each LVS router node must have IP forwarding turned on in the kernel. Log in as root and change the line which reads net.ipv4.ip_forward = 0 in /etc/sysctl.conf to the following: The changes take effect when you reboot the system. To check if IP forwarding is turned on, issue the following command as root: /sbin/sysctl net.ipv4.ip_forward If the above command returns a 1 , then IP forwarding is enabled. If it returns a 0 , then you can turn it on manually using the following command: /sbin/sysctl -w net.ipv4.ip_forward=1

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net.ipv4.ip_forward = 1
Chapter 4. Using Keycloak The Keycloak backend plugin, which integrates Keycloak into Developer Hub, has the following capabilities: Synchronization of Keycloak users in a realm. Synchronization of Keycloak groups and their users in a realm. 4.1. Importing users and groups in Developer Hub using the Keycloak plugin After configuring the plugin successfully, the plugin imports the users and groups each time when started. Note If you set up a schedule, users and groups will also be imported. After the first import is complete, you can select User to list the users from the catalog page: You can see the list of users on the page: When you select a user, you can see the information imported from Keycloak: You can also select a group, view the list, and select or view the information imported from Keycloak for a group:

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3.3. Growing a File System on a Logical Volume To grow a file system on a logical volume, perform the following steps: Make a new physical volume. Extend the volume group that contains the logical volume with the file system you are growing to include the new physical volume. Extend the logical volume to include the new physical volume. Grow the file system. If you have sufficient unallocated space in the volume group, you can use that space to extend the logical volume instead of performing steps 1 and 2.

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Chapter 21. console This chapter describes the commands under the console command. 21.1. console log show Show server's console output Usage: Table 21.1. Positional arguments Value Summary <server> Server to show console log (name or id) Table 21.2. Command arguments Value Summary -h, --help Show this help message and exit --lines <num-lines> Number of lines to display from the end of the log (default=all) 21.2. console url show Show server's remote console URL Usage: Table 21.3. Positional arguments Value Summary <server> Server to show url (name or id) Table 21.4. Command arguments Value Summary -h, --help Show this help message and exit --novnc Show novnc console url (default) --xvpvnc Show xvpvnc console url --spice Show spice console url --rdp Show rdp console url --serial Show serial console url --mks Show webmks console url Table 21.5. Output formatter options Value Summary -f {json,shell,table,value,yaml}, --format {json,shell,table,value,yaml} The output format, defaults to table -c COLUMN, --column COLUMN Specify the column(s) to include, can be repeated to show multiple columns Table 21.6. JSON formatter options Value Summary --noindent Whether to disable indenting the json Table 21.7. Shell formatter options Value Summary --prefix PREFIX Add a prefix to all variable names Table 21.8. Table formatter options Value Summary --max-width <integer> Maximum display width, <1 to disable. you can also use the CLIFF_MAX_TERM_WIDTH environment variable, but the parameter takes precedence. --fit-width Fit the table to the display width. implied if --max- width greater than 0. Set the environment variable CLIFF_FIT_WIDTH=1 to always enable --print-empty Print empty table if there is no data to show.

Commands:
openstack console log show [-h] [--lines <num-lines>] <server>
openstack console url show [-h] [-f {json,shell,table,value,yaml}] [-c COLUMN] [--noindent] [--prefix PREFIX] [--max-width <integer>] [--fit-width] [--print-empty] [--novnc | --xvpvnc | --spice | --rdp | --serial | --mks] <server>
Chapter 45. Networking Cisco usNIC driver Cisco Unified Communication Manager (UCM) servers have an optional feature to provide a Cisco proprietary User Space Network Interface Controller (usNIC), which allows performing Remote Direct Memory Access (RDMA)-like operations for user-space applications. The libusnic_verbs driver, which is available as a Technology Preview, makes it possible to use usNIC devices via standard InfiniBand RDMA programming based on the Verbs API. (BZ#916384) Cisco VIC kernel driver The Cisco VIC Infiniband kernel driver, which is available as a Technology Preview, allows the use of Remote Directory Memory Access (RDMA)-like semantics on proprietary Cisco architectures. (BZ#916382) Trusted Network Connect Trusted Network Connect, available as a Technology Preview, is used with existing network access control (NAC) solutions, such as TLS, 802.1X, or IPsec to integrate endpoint posture assessment; that is, collecting an endpoint's system information (such as operating system configuration settings, installed packages, and others, termed as integrity measurements). Trusted Network Connect is used to verify these measurements against network access policies before allowing the endpoint to access the network. (BZ#755087) SR-IOV functionality in the qlcnic driver Support for Single-Root I/O virtualization (SR-IOV) has been added to the qlcnic driver as a Technology Preview. Support for this functionality will be provided directly by QLogic, and customers are encouraged to provide feedback to QLogic and Red Hat. Other functionality in the qlcnic driver remains fully supported. (BZ#1259547) The flower classifier with off-loading support flower is a Traffic Control (TC) classifier intended to allow users to configure matching on well-known packet fields for various protocols. It is intended to make it easier to configure rules over the u32 classifier for complex filtering and classification tasks. flower also supports the ability to off-load classification and action rules to underlying hardware if the hardware supports it. The flower TC classifier is now provided as a Technology Preview. (BZ#1393375)

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8.2. Consoles and Logging During the Installation The following sections describe how to access logs and an interactive shell during the installation. This is useful when troubleshooting problems, but should not be necessary in most cases. 8.2.1. Accessing Consoles The Red Hat Enterprise Linux installer uses the tmux terminal multiplexer to display and control several windows you can use in addition to the main interface. Each of these windows serves a different purpose - they display several different logs, which can be used to troubleshoot any issues during the installation, and one of the windows provides an interactive shell prompt with root privileges, unless this prompt was specifically disabled using a boot option or a Kickstart command. Note In general, there is no reason to leave the default graphical installation environment unless you need to diagnose an installation problem. The terminal multiplexer is running in virtual console 1. To switch from the graphical installation environment to tmux , press Ctrl + Alt + F1 . To go back to the main installation interface which runs in virtual console 6, press Ctrl + Alt + F6 . Note If you choose text mode installation, you will start in virtual console 1 ( tmux ), and switching to console 6 will open a shell prompt instead of a graphical interface. The console running tmux has 5 available windows; their contents are described in the table below, along with keyboard shortcuts used to access them. Note that the keyboard shortcuts are two-part: first press Ctrl + b , then release both keys, and press the number key for the window you want to use. You can also use Ctrl + b n and Ctrl + b p to switch to the or tmux window, respectively. Table 8.1. Available tmux Windows Shortcut Contents Ctrl + b 1 Main installation program window. Contains text-based prompts (during text mode installation or if you use VNC Direct Mode), and also some debugging information. Ctrl + b 2 Interactive shell prompt with root privileges. Ctrl + b 3 Installation log; displays messages stored in /tmp/anaconda.log . Ctrl + b 4 Storage log; displays messages related storage devices from kernel and system services, stored in /tmp/storage.log . Ctrl + b 5 Program log; displays messages from other system utilities, stored in /tmp/program.log . In addition to displaying diagnostic information in tmux windows, Anaconda also generates several log files, which can be transferred from the installation system. These log files are described in Table 9.1, "Log Files Generated During the Installation" , and directions for transferring them from the installation system are available in Chapter 9, Troubleshooting Installation on 64-bit AMD, Intel, and ARM Systems . 8.2.2. Saving Screenshots You can press Shift + Print Screen at any time during the graphical installation to capture the current screen. These screenshots are saved to /tmp/anaconda-screenshots/ . Additionally, you can use the autostep --autoscreenshot command in a Kickstart file to capture and save each step of the installation automatically. See Section 27.3.1, "Kickstart Commands and Options" for details.

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