mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 9. Setting up a printer In GNOME, you can set up printing using the Settings application. 9.1. Accessing printer settings in GNOME Procedure Use one of the approaches described in Launching applications to start the Settings application. Moreover, you can also start the Settings application from the system menu in the upper right corner by clicking on the "Settings" icon. When the Settings application GUI appears, go to Printers . Figure 9.1. GNOME Control center configuration tool 9.2. Adding a new printer in Settings You can add a new printer using the Settings application. Prerequisites Click the Unlock button, which appears near the upper-right corner of the Printers screen, and authenticate as one of the following users: Superuser Any user with the administrative access provided by sudo (users listed within /etc/sudoers ) Any user belonging to the printadmin group in /etc/group Procedure Open the Printers dialog. Click on Unlock and authenticate. Select one of the available printers (including also network printers), or enter printer IP address or the host name of a printer server. Confirm your selection by clicking Add in the top right corner. 9.3. Printing a test page in Settings You can print a test page to make sure that the printer functions properly. Prerequisites A printer has been set up. Procedure Click the settings (⚙\ufe0f) button on the right to display a settings menu for the selected printer: Click Printing Options Test Page .

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Chapter 63. Enabling notifications in the Red Hat Customer Portal You can enable notifications in the Red Hat Customer Portal to receive product updates and announcements. These notifications inform you of updated or added documentation, product releases, and patch updates related to your installation. With notifications enabled, you can more readily apply product updates as they become available in the Red Hat Customer Portal to keep your distribution current with the latest enhancements and fixes. Prerequisites You have a Red Hat Customer Portal account and are logged in. Procedure In the top-right corner of the Red Hat Customer Portal window, click your profile name and click Notifications . Select the Notifications tab and click Manage Notifications . to Follow , select Products from the drop-down menu, and then select Red Hat Process Automation Manager from the drop-down menu that appears. Click Save Notification to finish. You can add notifications for any other products as needed in the same way.

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7.34. ctdb 7.34.1. RHBA-2013:0337 - ctdb bug fix update Updated ctdb packages that fix various bugs and are now available for Red Hat Enterprise Linux 6. The ctdb packages provide a clustered database based on Samba's Trivial Database (TDB) used to store temporary data. Note The ctbd packages have been upgraded to upstream version 1.0.114.5, which provides a number of bug fixes over the version. (BZ# 838885 ) Bug Fixes BZ#758367 While running ctdb on the GFS2 file system, ctdb could ban a stable node when another node was started or stopped. This bug has been fixed by the rebase and stable nodes get no longer banned in the described scenario. BZ# 821715 Previously, on the Glusterfs file system, the ctdb lock file and configuration files were shared. Consequently, the ctdbd daemon running on a node terminated unexpectedly when another node in the cluster was brought down. This bug has been fixed by the rebase and ctdbd no longer crashes in the described scenario. BZ# 866670 After removing a ctdb node, the "ctdb status" command reported the same number of nodes as before the node was removed. A patch has been provided to address this issue and "ctdb status" now returns an accurate number of nodes after a remove operation. Users of ctdb are advised to upgrade to these updated packages, which fix these bugs.

Commands:
8.263. xguest 8.263.1. RHBA-2014:0538 - xguest bug fix update An updated xguest package that fixes two bugs is now available for Red Hat Enterprise Linux 6. The xguest package sets up the xguest user which can be used as a temporary account to switch to or as a kiosk user account. These accounts are disabled unless SELinux is in enforcing mode. Bug Fixes BZ# 877016 Due to a bug in the dependency requirements for the preinstall scriptlet, installing the xguest package failed because of a dependency problem. This update adds the selinux-policy-targeted package to the dependency list, and installing xguest now works as expected. BZ# 1081413 Previously, the xguest README file did not reflect the current state of the defined xguest SELinux booleans in the SELinux policy. This update modifies the README file to correctly document the current state of the aforementioned booleans. Users of xguest are advised to upgrade to this updated package, which fixes these bugs.

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15.15. Exporting the Replication Changelog In certain situations, such as when you want to encrypt the replication changelog, you must export the changelog as part of the process. Complete this procedure to export the changelog. Prerequisites Replication is enabled on the Directory Server instance. Procedure To export the changelog to the /tmp/changelog.ldif file, enter: Note that the dirsrv user requires appropriate file system permissions to create the specified file.

Commands:
dsconf -D "cn=Directory Manager" ldap://server.example.com replication dump-changelog -o /tmp/changelog.ldif
B.18.2. RHBA-2010:0877 - dracut bug fix update Updated dracut packages that fix a bug are now available for Red Hat Enterprise Linux 6. The dracut package is an event-driven initramfs generator infrastructure based around udev. The initramfs is loaded together with the kernel at boot time and initializes the system, so it can read and boot from the root partition. Bug Fix BZ# 651402 Prior to this update, the udev rules used by dracut may have caused the merged logical volume management (LVM) snapshots to be accessed. Consequent to this, I/O errors appeared in the log. With this update, dracut's internal udev rules have been updated to ignore those internal devices, and dracut now works as expected. Users of dracut are advised to upgrade to these updated packages, which fix this bug.

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Chapter 41. Desktop Wayland available as a Technology Preview The Wayland display server protocol is now available in Red Hat Enterprise Linux as a Technology Preview. This update adds the dependent packages required to enable Wayland support in GNOME, which supports fractional scaling. Wayland uses the libinput library as its input driver. The following features are currently unavailable or do not work correctly: Multiple GPU support is impossible. The NVIDIA binary driver does not work under Wayland . The xrandr utility does not work under Wayland due to its different approach to handling, resolutions, rotations, and layout. Screen recording, remote desktop, and accessibility do not always work correctly under Wayland . No clipboard manager is available. It is impossible to restart GNOME Shell under Wayland . Wayland ignores keyboard grabs issued by X11 applications, such as virtual machines viewers. (BZ#1481411) Fractional Scaling available as a Technology Preview Starting with Red Hat Enterprise Linux 7.5, GNOME provides, as a Technology Preview, fractional scaling to address problems with monitors whose DPI lies in the middle between lo (scale 1) and hi (scale 2). Due to technical limitations, fractional scaling is available only on Wayland. (BZ# 1481395 )

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Chapter 3. Internal storage services Red Hat OpenShift Data Foundation service is available for consumption internally to the Red Hat OpenShift Container Platform running on the following infrastructure: Amazon Web Services Bare metal VMware vSphere Microsoft Azure Google Cloud [Technology Preview] Red Hat Virtualization 4.4.x or higher (IPI) Red Hat OpenStack 13 or higher (IPI) [Technology Preview] IBM Power IBM Z and LinuxONE Creation of an internal cluster resource will result in the internal provisioning of the OpenShift Data Foundation base services, and make additional storage classes available to applications.

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Chapter 3. Allowing user access to the Multicloud Object Gateway Console To allow access to the Multicloud Object Gateway (MCG) Console to a user, ensure that the user meets the following conditions: User is in cluster-admins group. User is in system:cluster-admins virtual group. Prerequisites A running OpenShift Data Foundation Platform. Procedure Enable access to the MCG console. Perform the following steps once on the cluster : Create a cluster-admins group. Bind the group to the cluster-admin role. Add or remove users from the cluster-admins group to control access to the MCG console. To add a set of users to the cluster-admins group : where <user-name> is the name of the user to be added. Note If you are adding a set of users to the cluster-admins group, you do not need to bind the newly added users to the cluster-admin role to allow access to the OpenShift Data Foundation dashboard. To remove a set of users from the cluster-admins group : where <user-name> is the name of the user to be removed. Verification steps On the OpenShift Web Console, login as a user with access permission to Multicloud Object Gateway Console. Navigate to Storage OpenShift Data Foundation . In the Storage Systems tab, select the storage system and then click Overview Object tab. Select the Multicloud Object Gateway link. Click Allow selected permissions .

Commands:
oc adm groups new cluster-admins
oc adm policy add-cluster-role-to-group cluster-admin cluster-admins
oc adm groups add-users cluster-admins <user-name> <user-name> <user-name>
oc adm groups remove-users cluster-admins <user-name> <user-name> <user-name>
22.8. Understanding Leap Seconds Greenwich Mean Time (GMT) was derived by measuring the solar day, which is dependent on the Earth's rotation. When atomic clocks were first made, the potential for more accurate definitions of time became possible. In 1958, International Atomic Time (TAI) was introduced based on the more accurate and very stable atomic clocks. A more accurate astronomical time, Universal Time 1 (UT1), was also introduced to replace GMT. The atomic clocks are in fact far more stable than the rotation of the Earth and so the two times began to drift apart. For this reason UTC was introduced as a practical measure. It is kept within one second of UT1 but to avoid making many small trivial adjustments it was decided to introduce the concept of a leap second in order to reconcile the difference in a manageable way. The difference between UT1 and UTC is monitored until they drift apart by more than half a second. Then only is it deemed necessary to introduce a one second adjustment, forward or backward. Due to the erratic nature of the Earth's rotational speed, the need for an adjustment cannot be predicted far into the future. The decision as to when to make an adjustment is made by the International Earth Rotation and Reference Systems Service (IERS) . However, these announcements are important only to administrators of Stratum 1 servers because NTP transmits information about pending leap seconds and applies them automatically.

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function::ubacktrace Name function::ubacktrace - Hex backtrace of current task stack. EXPERIMENTAL! Synopsis Arguments None Description Return a string of hex addresses that are a backtrace of the stack of the current task. Output may be truncated as per maximum string length. Returns empty string when current probe point cannot determine user backtrace. Note To get (full) backtraces for user space applications and shared shared libraries not mentioned in the current script run stap with -d /path/to/exe-or-so and/or add --ldd to load all needed unwind data.

Commands:
function ubacktrace:string()
18.3.5. Target Options Once a packet has matched a particular rule, the rule can direct the packet to a number of different targets that decide its fate and, possibly, take additional actions. Each chain has a default target, which is used if none of the rules on that chain match a packet or if none of the rules which match the packet specify a target. The following are the standard targets: <user-defined-chain> - Replace <user-defined-chain> with the name of a user-defined chain within the table. This target passes the packet to the target chain. ACCEPT - Allows the packet to successfully move on to its destination or another chain. DROP - Drops the packet without responding to the requester. The system that sent the packet is not notified of the failure. QUEUE - The packet is queued for handling by a user-space application. RETURN - Stops checking the packet against rules in the current chain. If the packet with a RETURN target matches a rule in a chain called from another chain, the packet is returned to the first chain to resume rule checking where it left off. If the RETURN rule is used on a built-in chain and the packet cannot move up to its chain, the default target for the current chain decides what action to take. In addition to these standard targets, various other targets may be used with extensions called target modules . For more information about match option modules, refer to Section 18.3.4.4, "Additional Match Option Modules" . There are many extended target modules, most of which only apply to specific tables or situations. A couple of the most popular target modules included by default in Red Hat Enterprise Linux are: LOG - Logs all packets that match this rule. Since the packets are logged by the kernel, the /etc/syslog.conf file determines where these log entries are written. By default, they are placed in the /var/log/messages file. Additional options can be used after the LOG target to specify the way in which logging occurs: --log-level - Sets the priority level of a logging event. A list of priority levels can be found within the syslog.conf man page. --log-ip-options - Logs any options set in the header of a IP packet. --log-prefix - Places a string of up to 29 characters before the log line when it is written. This is useful for writing syslog filters for use in conjunction with packet logging. --log-tcp-options - Logs any options set in the header of a TCP packet. --log-tcp-sequence - Writes the TCP sequence number for the packet in the log. REJECT - Sends an error packet back to the remote system and drops the packet. The REJECT target accepts --reject-with <type> (where <type> is the rejection type) allowing more detailed information to be sent back with the error packet. The message port-unreachable is the default <type> error given if no other option is used. For a full list of <type> options, refer to the iptables man page. Other target extensions, including several that are useful for IP masquerading using the nat table or with packet alteration using the mangle table, can be found in the iptables man page.

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5.154. libreoffice 5.154.1. RHSA-2012:1135 - Important: libreoffice security update Updated libreoffice packages that fix multiple security issues are now available for Red Hat Enterprise Linux 6. The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link(s) associated with each description below. LibreOffice is an open source, community-developed office productivity suite. It includes the key desktop applications, such as a word processor, spreadsheet application, presentation manager, formula editor, and a drawing program. Security Fix CVE-2012-2665 Multiple heap-based buffer overflow flaws were found in the way LibreOffice processed encryption information in the manifest files of OpenDocument Format files. An attacker could provide a specially-crafted OpenDocument Format file that, when opened in a LibreOffice application, would cause the application to crash or, potentially, execute arbitrary code with the privileges of the user running the application. Upstream acknowledges Timo Warns as the original reporter of these issues. All LibreOffice users are advised to upgrade to these updated packages, which contain backported patches to correct these issues. All running instances of LibreOffice applications must be restarted for this update to take effect.

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A.7. Evaluating Virtual Machine Custom Properties in a VDSM Hook Each key set in the Custom Properties field for a virtual machine is appended as an environment variable when calling hook scripts. Although the regular expressions used to validate the Custom Properties field provide some protection you should ensure that your scripts also validate that the inputs provided match their expectations. Example A.3. Evaluating Custom Properties This short Python example checks for the existence of the custom property key1 . If the custom property is set then the value is printed to standard error. If the custom property is not set then no action is taken. #!/usr/bin/python import os import sys if os.environ.has_key('key1'): sys.stderr.write('key1 value was : %s\n' % os.environ['key1']) else: sys.exit(0)

Commands:
#!/usr/bin/python import os import sys if os.environ.has_key('key1'): sys.stderr.write('key1 value was : %s\n' % os.environ['key1']) else: sys.exit(0)
E.2.22. /proc/mtrr This file refers to the current Memory Type Range Registers (MTRRs) in use with the system. If the system architecture supports MTRRs, then the /proc/mtrr file may look similar to the following: MTRRs are used with the Intel P6 family of processors (Pentium II and higher) and control processor access to memory ranges. When using a video card on a PCI or AGP bus, a properly configured /proc/mtrr file can increase performance more than 150%. Most of the time, this value is properly configured by default. More information on manually configuring this file can be found locally at the following location:

Commands:
reg00: base=0x00000000 ( 0MB), size= 256MB: write-back, count=1 reg01: base=0xe8000000 (3712MB), size= 32MB: write-combining, count=1
/usr/share/doc/kernel-doc- <kernel_version> /Documentation/ <arch> /mtrr.txt
Chapter 1. Migration Overview When you specify a backup file during self-hosted engine deployment, the Manager backup is restored on a new virtual machine, with a dedicated self-hosted engine storage domain. Deploying on a fresh host is highly recommended; if the host used for deployment existed in the backed up environment, it will be removed from the restored database to avoid conflicts in the new environment. At least two self-hosted engine nodes are required for the Manager virtual machine to be highly available. You can add new nodes, or convert existing hosts. The migration involves the following key steps: Install a new host to deploy the self-hosted engine on. You can use either host type: Red Hat Virtualization Host Red Hat Enterprise Linux Prepare storage for the self-hosted engine storage domain. You can use one of the following storage types: NFS iSCSI Fibre Channel (FCP) Red Hat Gluster Storage Update the original Manager to the latest minor version before you back it up. Back up the original Manager using the engine-backup tool. Deploy a new self-hosted engine and restore the backup. Enable the Manager repositories on the new Manager virtual machine. Convert regular hosts to self-hosted engine nodes that can host the new Manager. This procedure assumes that you have access and can make changes to the original Manager. Prerequisites FQDNs prepared for your Manager and the deployment host. Forward and reverse lookup records must both be set in the DNS. The new Manager must have the same FQDN as the original Manager. The management network ( ovirtmgmt by default) must be configured as a VM network , so that it can manage the Manager virtual machine.

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2.5. Storage Utilization The Storage Utilization section shows the storage utilization in a heatmap. Figure 2.6. Storage Utilization The heatmap shows the average utilization of the storage for the last 24 hours. The formula used to calculate the storage usage by the cluster is the total utilization of the storage in the cluster. This is calculated by using the average storage utilization for each host over the last 24 hours to find the total average usage of the storage by the cluster. Hovering over the heatmap displays the storage domain name. Clicking on the heatmap navigates to Storage Domains with the storage domains sorted by utilization.

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13.6. Partial Results JBoss Data Virtualization provides the capability to obtain "partial results" in the event of data source unavailability or failure. This is especially useful when unioning information from multiple sources, or when doing a left outer join, where you are 'appending' columns to a master record but still want the record if the extra information is not available. A source is considered to be 'unavailable' if the connection factory associated with the source issues an exception in response to a query. The exception will be propagated to the query processor, where it will become a warning on the statement. See Red Hat JBoss Data Virtualization Development Guide: Client Development for more on Partial Results Mode and SQLWarnings.

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8.5.2. Installing Additional Yum Plug-ins Yum plug-ins usually adhere to the yum-plugin- plugin_name package-naming convention, but not always: the package which provides the presto plug-in is named yum-presto , for example. You can install a Yum plug-in in the same way you install other packages. For instance, to install the security plug-in, type the following at a shell prompt:

Commands:
~]# yum install yum-plugin-security
5.303. slf4j 5.303.1. RHBA-2012:1239 - slf4j bug fix update Updated slf4j packages that fix one bug are now available for Red Hat Enterprise Linux 6. The Simple Logging Facade (SLF4J) for Java serves as a simple facade for various logging APIs allowing the end-user to plug in the desired implementation at deployment time. Bug Fix BZ# 831933 , BZ# 828644 The slf4j packages contained a non-functional dummy API implementation which was not supposed to be used. This dummy implementation was always selected instead of other implementations and UnsupportedOperationException was thrown. The dummy API implementation has been removed, so that user-supplied implementation is now always chosen, and slf4j works as expected. All users of slf4j are advised to upgrade to these updated packages, which fix this bug.

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29.2. Configuring OProfile Before OProfile can be run, it must be configured. At a minimum, selecting to monitor the kernel (or selecting not to monitor the kernel) is required. The following sections describe how to use the opcontrol utility to configure OProfile. As the opcontrol commands are executed, the setup options are saved to the /root/.oprofile/daemonrc file. 29.2.1. Specifying the Kernel First, configure whether OProfile should monitor the kernel. This is the only configuration option that is required before starting OProfile. All others are optional. To monitor the kernel, execute the following command as root: Important The debuginfo package for the kernel must be installed (which contains the uncompressed kernel) in order to monitor the kernel. To configure OProfile not to monitor the kernel, execute the following command as root: This command also loads the oprofile kernel module, if it is not already loaded, and creates the /dev/oprofile/ directory, if it does not already exist. See Section 29.6, "Understanding /dev/oprofile/ " for details about this directory. Setting whether samples should be collected within the kernel only changes what data is collected, not how or where the collected data is stored. To generate different sample files for the kernel and application libraries, see Section 29.2.3, "Separating Kernel and User-space Profiles" .

Commands:
~]# opcontrol --setup --vmlinux=/usr/lib/debug/lib/modules/`uname -r`/vmlinux
~]# opcontrol --setup --no-vmlinux