mtpti5iD/redhat-docs_dataset huggingface dataset:
Chapter 5. Pools, placement groups, and CRUSH configuration As a storage administrator, you can choose to use the Red Hat Ceph Storage default options for pools, placement groups, and the CRUSH algorithm or customize them for the intended workload. 5.1. Prerequisites Installation of the Red Hat Ceph Storage software. 5.2. Pools placement groups and CRUSH When you create pools and set the number of placement groups for the pool, Ceph uses default values when you do not specifically override the defaults. Important Red Hat recommends overriding some of the defaults. Specifically, set a pool's replica size and override the default number of placement groups. You can set these values when running pool commands. By default, Ceph makes 3 replicas of objects. If you want to set 4 copies of an object as the default value, a primary copy and three replica copies, reset the default values as shown in osd_pool_default_size . If you want to allow Ceph to write a lesser number of copies in a degraded state, set osd_pool_default_min_size to a number less than the osd_pool_default_size value. Example Ensure you have a realistic number of placement groups. Red Hat recommends approximately 100 per OSD. For example, total number of OSDs multiplied by 100 divided by the number of replicas, that is, osd_pool_default_size . For 10 OSDs and osd_pool_default_size = 4, we would recommend approximately (100 * 10) / 4 = 250. Example 5.3. Additional Resources See all the Red Hat Ceph Storage pool, placement group, and CRUSH configuration options in Appendix E for specific option descriptions and usage.

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ceph config set global osd_pool_default_size 4 # Write an object 4 times. ceph config set global osd_pool_default_min_size 1 # Allow writing one copy in a degraded state.
ceph config set global osd_pool_default_pg_num 250 ceph config set global osd_pool_default_pgp_num 250
Chapter 6. Connecting your systems to Red Hat Insights When using Red Hat Insights for Red Hat Enterprise Linux hosted on the Red Hat Hybrid Cloud Console, each system needs to be able to communicate with Insights so that Red Hat can provide system analysis. If constraints are in place that prevent your systems from directly accessing the Internet, such as a firewall or other layers of security, additional configuration might be required. A system can connect to Insights in the following ways: Directly Through Red Hat Satellite Through Insights proxy Through your own proxy server Information is provided to help you to connect your systems to Insights. 6.1. Connecting to Red Hat Insights through Red Hat Satellite Important If you are a Red Hat Satellite user then Satellite is used as the single point of connection in your network with all communications going from the host to the Satellite to Insights. Satellite does this automatically so you do not need to configure connectivity. If you are not a Satellite user then you need to either directly communicate to Red Hat Insights or set up a web proxy. 6.2. Connecting to Red Hat Insights through Insights proxy Insights proxy provides capabilities and features for securely and efficiently connecting your systems to Red Hat Insights. To make it simpler and easier for you, Red Hat Insights provides a proxy, which is included with your RHEL subscription. Insights proxy routes all Red Hat traffic through the proxy with a config script hosted on the proxy server that you use to configure each host system. For detailed information about how to install and configure Red Hat Insights proxy, see Connecting to Red Hat Insights through Insights proxy . 6.3. Connecting to Red Hat Insights through your own proxy You might choose to use a web proxy of your choice to act as a gateway between the public Internet and your private network, and configure a web config file on each host. This is a good security measure to protect your systems from malicious activity. To connect your systems to Insights you must add hostnames, ports, and allow additional URLs. For guidance about how to connect to Insights by using your own proxy, see Connecting to Red Hat Insights through your own proxy .

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Chapter 4. Adding systems to a group from the Group details view In the Insights Inventory application, you can add several systems to a group from the Group details view. This allows you to manage the systems simultaneously, along with the other members in the group. For example, you can easily update systems that have an update available. Prerequisites You have a Red Hat Hybrid Cloud Console account. You have registered the systems you plan to group with the Insights Inventory application. Procedure Access Red Hat Hybrid Cloud Console platform and log in. From the console dashboard, navigate to Red Hat Insights > RHEL > Inventory > Groups . In the Groups page: Click the group to which you want to add systems from the Inventory. The group page opens, showing the current systems. Click Add systems . The Add systems window opens. From the Immutable (OSTree) tab, select the systems that you want to add. Click Add systems . A popup alert informs you that the action was successful. Verification If adding the multiple systems to the group was successful, you can see the systems that were added to the group.

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24.3. Configuring an Exported File System for Diskless Clients The root directory of the exported file system (used by diskless clients in the network) is shared via NFS. Configure the NFS service to export the root directory by adding it to /etc/exports . For instructions on how to do so, refer to Section 9.7.1, "The /etc/exports Configuration File" . To accommodate completely diskless clients, the root directory should contain a complete Red Hat Enterprise Linux installation. You can synchronize this with a running system via rsync , as in: Replace hostname.com with the hostname of the running system with which to synchronize via rsync . The /exported/root/directory is the path to the exported file system. Alternatively, you can also use yum with the --installroot option to install Red Hat Enterprise Linux to a specific location. For example: The file system to be exported still needs to be configured further before it can be used by diskless clients. To do this, perform the following procedure: Procedure 24.2. Configure file system Configure the exported file system's /etc/fstab to contain (at least) the following configuration: Select the kernel that diskless clients should use ( vmlinuz- kernel-version ) and copy it to the tftp boot directory: Create the initrd (i.e. initramfs- kernel-version .img ) with network support: Copy the resulting initramfs- kernel-version .img into the tftp boot directory as well. Edit the default boot configuration to use the initrd and kernel inside /var/lib/tftpboot . This configuration should instruct the diskless client's root to mount the exported file system ( /exported/root/directory ) as read-write. To do this, configure /var/lib/tftpboot/pxelinux.cfg/default with the following: Replace server-ip with the IP address of the host machine on which the tftp and DHCP services reside. The NFS share is now ready for exporting to diskless clients. These clients can boot over the network via PXE.

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rsync -a -e ssh --exclude='/proc/*' --exclude='/sys/*' hostname.com :/ /exported/root/directory
groupinstall Base --installroot= /exported/root/directory
none /tmp tmpfs defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0
cp /boot/vmlinuz- kernel-version /var/lib/tftpboot/
dracut initramfs- kernel-version .img kernel-version
default rhel6 label rhel6 kernel vmlinuz- kernel-version append initrd=initramfs- kernel-version .img root=nfs: server-ip : /exported/root/directory rw
Chapter 5. Technology Previews Technology Preview features included with AMQ Streams 2.5. Important Technology Preview features are not supported with Red Hat production service-level agreements (SLAs) and might not be functionally complete; therefore, Red Hat does not recommend implementing any Technology Preview features in production environments. This Technology Preview feature provides early access to upcoming product innovations, enabling you to test functionality and provide feedback during the development process. For more information about the support scope, see Technology Preview Features Support Scope . 5.1. KRaft mode Apache Kafka is in the process of phasing out the need for ZooKeeper. You can now try deploying a Kafka cluster in KRaft (Kafka Raft metadata) mode without ZooKeeper as a technology preview. Caution This mode is intended only for development and testing, and must not be enabled for a production environment. Currently, the KRaft mode in AMQ Streams has the following major limitations: Moving from Kafka clusters with ZooKeeper to KRaft clusters or the other way around is not supported. Upgrades and downgrades of Apache Kafka versions are not supported. JBOD storage with multiple disks is not supported. Many configuration options are still in development. See Running Kafka in KRaft mode . 5.2. Kafka Static Quota plugin configuration Use the technology preview of the Kafka Static Quota plugin to set throughput and storage limits on brokers in your Kafka cluster. You can set a byte-rate threshold and storage quotas to put limits on the clients interacting with your brokers. Example Kafka Static Quota plugin configuration client.quota.callback.class= io.strimzi.kafka.quotas.StaticQuotaCallback client.quota.callback.static.produce= 1000000 client.quota.callback.static.fetch= 1000000 client.quota.callback.static.storage.soft= 400000000000 client.quota.callback.static.storage.hard= 500000000000 client.quota.callback.static.storage.check-interval= 5 See Setting limits on brokers using the Kafka Static Quota plugin .

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client.quota.callback.class= io.strimzi.kafka.quotas.StaticQuotaCallback client.quota.callback.static.produce= 1000000 client.quota.callback.static.fetch= 1000000 client.quota.callback.static.storage.soft= 400000000000 client.quota.callback.static.storage.hard= 500000000000 client.quota.callback.static.storage.check-interval= 5
13.9. Language Support To install support for additional locales and language dialects, select Language Support from the Installation Summary screen. Use your mouse to select the language for which you would like to install support. In the left panel, select your language of choice, for example Espanol . Then you can select a locale specific to your region in the right panel, for example Espanol (Costa Rica) . You can select multiple languages and multiple locales. The selected languages are highlighted in bold in the left panel. Figure 13.6. Configuring Language Support Once you have made your selections, click Done to return to the Installation Summary screen. Note To change your language support configuration after you have completed the installation, visit the Region & Language section of the Settings dialog window.

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21.3.11. Additional Resources To learn more about printing on Red Hat Enterprise Linux, see the following resources. 21.3.11.1. Installed Documentation man lp The manual page for the lp command that allows you to print files from the command line. man lpr The manual page for the lpr command that allows you to print files from the command line. man cancel The manual page for the command-line utility to remove print jobs from the print queue. man mpage The manual page for the command-line utility to print multiple pages on one sheet of paper. man cupsd The manual page for the CUPS printer daemon. man cupsd.conf The manual page for the CUPS printer daemon configuration file. man classes.conf The manual page for the class configuration file for CUPS. man lpstat The manual page for the lpstat command, which displays status information about classes, jobs, and printers. 21.3.11.2. Useful Websites http://www.linuxprinting.org/ GNU/Linux Printing contains a large amount of information about printing in Linux. http://www.cups.org/ Documentation, FAQs, and newsgroups about CUPS.

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probe::ipmib.ReasmReqds Name probe::ipmib.ReasmReqds - Count number of packet fragments reassembly requests Synopsis ipmib.ReasmReqds Values op value to be added to the counter (default value of 1) skb pointer to the struct sk_buff being acted on Description The packet pointed to by skb is filtered by the function ipmib_filter_key . If the packet passes the filter is is counted in the global ReasmReqds (equivalent to SNMP's MIB IPSTATS_MIB_REASMREQDS)

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Chapter 3. Networking dashboards Networking metrics are viewable in dashboards within the OpenShift Container Platform web console, under Observe Dashboards . 3.1. Network Observability Operator If you have the Network Observability Operator installed, you can view network traffic metrics dashboards by selecting the Netobserv dashboard from the Dashboards drop-down list. For more information about metrics available in this Dashboard , see Network Observability metrics dashboards . 3.2. Networking and OVN-Kubernetes dashboard You can view both general networking metrics as well as OVN-Kubernetes metrics from the dashboard. To view general networking metrics, select Networking/Linux Subsystem Stats from the Dashboards drop-down list. You can view the following networking metrics from the dashboard: Network Utilisation , Network Saturation , and Network Errors . To view OVN-Kubernetes metrics select Networking/Infrastructure from the Dashboards drop-down list. You can view the following OVN-Kuberenetes metrics: Networking Configuration , TCP Latency Probes , Control Plane Resources , and Worker Resources . 3.3. Ingress Operator dashboard You can view networking metrics handled by the Ingress Operator from the dashboard. This includes metrics like the following: Incoming and outgoing bandwidth HTTP error rates HTTP server response latency To view these Ingress metrics, select Networking/Ingress from the Dashboards drop-down list. You can view Ingress metrics for the following categories: Top 10 Per Route , Top 10 Per Namespace , and Top 10 Per Shard .

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Appendix A. RHEL 8 repositories Before the upgrade, ensure you have appropriate repositories enabled as described in step 4 of the procedure in Preparing a RHEL 8 system for the upgrade . If you plan to use Red Hat Subscription Manager during the upgrade, you must enable the following repositories before the upgrade by using the subscription-manager repos --enable repository_id command: Table A.1. RHEL 8 repositories Architecture Repository Repository ID 64-bit Intel and AMD Base rhel-8-for-x86_64-baseos-rpms AppStream rhel-8-for-x86_64-appstream-rpms 64-bit ARM Base rhel-8-for-aarch64-baseos-rpms Extras rhel-8-for-aarch64-appstream-rpms IBM POWER (little endian) Base rhel-8-for-ppc64le-baseos-rpms AppStream rhel-8-for-ppc64le-appstream-rpms IBM Z Base rhel-8-for-s390x-baseos-rpms AppStream rhel-8-for-s390x-appstream-rpms You can enable the following repositories before the upgrade by using the subscription-manager repos --enable repository_id command: Table A.2. Voluntary RHEL 8 repositories Architecture Repository Repository ID 64-bit Intel and AMD Code Ready Linux Builder codeready-builder-for-rhel-8-x86_64-rpms Supplementary rhel-8-for-x86_64-supplementary-rpms 64-bit ARM Code Ready Linux Builder codeready-builder-for-rhel-8-aarch64-rpms Supplementary rhel-8-for-aarch64-supplementary-rpms IBM POWER (little endian) Code Ready Linux Builder codeready-builder-for-rhel-8-ppc64le-rpms Supplementary rhel-8-for-ppc64le-supplementary-rpms IBM Z Code Ready Linux Builder codeready-builder-for-rhel-8-s390x-rpms Supplementary rhel-8-for-s390x-supplementary-rpms Note If you have enabled a RHEL 8 Code Ready Linux Builder or a RHEL 8 Supplementary repository before an in-place upgrade, Leapp enables the RHEL 8 CodeReady Linux Builder or the RHEL 8 Supplementary repositories, respectively. For more information, see the Package manifest . If you decide to use custom repositories, enable them per instructions in Configuring custom repositories .

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Chapter 26. Headless Systems When installing headless systems, you can only choose between an automated Kickstart installation and an interactive VNC installation using Connect Mode. For more information about automated Kickstart installation, see Section 27.3.1, "Kickstart Commands and Options" . The general process for interactive VNC installation is described below. Set up a network boot server to start the installation. Information about installing and performing basic configurating of a network boot server can be found in Chapter 24, Preparing for a Network Installation . Configure the server to use the boot options for a Connect Mode VNC installation. For information on these boot options, see Section 25.2.2, "Installing in VNC Connect Mode" . Follow the procedure for VNC Installation using Connect Mode as described in the procedure Procedure 25.2, "Starting VNC in Connect Mode" . However, when directed to boot the system, boot it from the network server instead of local media.

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4.12. Fence Virt (Multicast Mode) Table 4.13, "Fence virt (Multicast Mode) " lists the fence device parameters used by fence_xvm , the fence agent for virtual machines using multicast. Table 4.13. Fence virt (Multicast Mode) luci Field cluster.conf Attribute Description Name name A name for the Fence virt fence device. Timeout timeout Fencing timeout, in seconds. The default value is 30. Domain port (formerly domain ) Virtual machine (domain UUID or name) to fence. Delay (optional) delay Fencing delay, in seconds. The fence agent will wait the specified number of seconds before attempting a fencing operation. The default value is 0.

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Preface Red Hat OpenShift Data Foundation supports deployment on existing Red Hat OpenShift Container Platform (RHOCP) IBM Z clusters in connected or disconnected environments along with out-of-the-box support for proxy environments. Note See Planning your deployment and Preparing to deploy OpenShift Data Foundation for more information about deployment requirements. To deploy OpenShift Data Foundation, follow the appropriate deployment process for your environment: Internal Attached Devices mode Deploy using local storage devices External mode

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Chapter 6. Subscription Management Migration from RHN Classic to certificate-based RHN Red Hat Enterprise Linux 6.3 includes a new tool to migrate RHN Classic customers to the certificate-based RHN. For more information, refer to the Red Hat Enterprise Linux 6 Subscription Management Guide . Subscription Manager gpgcheck behavior Subscription Manager now disables gpgcheck for any repositories it manages which have an empty gpgkey . To re-enable the repository, upload the GPG keys, and ensure that the correct URL is added to your custom content definition. Firstboot System Registration In Red Hat Enterprise Linux 6.3, during firstboot system registration, registering to Certificate-based Subscription Management is now the default option. Server side deletes System profiles are now unregistered when they are deleted from the Customer Portal so that they no longer check in with certificate-based RHN. Preferred service levels Subscription manager now allows users to associate a machine with a preferred Service Level which impacts the auto subscription and healing logic. For more information on service levels, refer to the Red Hat Enterprise Linux 6 Subscription Management Guide . Limiting updates to a specific minor release Subscription manager now allows a user to select a specific release (for example, Red Hat Enterprise Linux 6.2), which will lock a machine to that release. Prior to this update, there was no way to limit package updates in the event newer packages became available as part of a later minor release (for example, Red Hat Enterprise Linux 6.3).

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7.3. Inkjet Printers An Inkjet printer uses one of the most popular printing technologies today. The relatively low cost and multi-purpose printing abilities make inkjet printers a good choice for small businesses and home offices. Inkjet printers use quick-drying, water-based inks and a printhead with a series of small nozzles that spray ink onto the surface of the paper. The printhead assembly is driven by a belt-fed motor that moves the printhead across the paper. Inkjets were originally manufactured to print in monochrome (black and white) only. However, the printhead has since been expanded and the nozzles increased to accommodate cyan, magenta, yellow, and black. This combination of colors (called CMYK ) allows the printing of images with nearly the same quality as a photo development lab (when using certain types of coated paper.) When coupled with crisp and highly readable text print quality, inkjet printers are a sound all-in-one choice for monochrome or color printing needs. 7.3.1. Inkjet Consumables Inkjet printers tend to be low cost and scale slightly upward based on print quality, extra features, and the ability to print on larger formats than the standard legal or letter paper sizes. While the one-time cost of purchasing an inkjet printer is lower than other printer types, there is the factor of inkjet consumables that must be considered. Because demand for inkjets is large and spans the computing spectrum from home to enterprise, the procurement of consumables can be costly. Note When shopping for an inkjet printer, always make sure you know what kind of ink cartridge(s) it requires. This is especially critical for color units. CMYK inkjet printers require ink for each color; however, the important point is whether each color is stored in a separate cartridge or not. Some printers use one multi-chambered cartridge; unless some sort of refilling process is possible, as soon as one color ink runs out, the entire cartridge must be replaced. Other printers use a multi-chambered cartridge for cyan, magenta, and yellow, but also have a separate cartridge for black. In environments where a great deal of text is printed, this type of arrangement can be beneficial. However, the best solution is to find a printer with separate cartridges for each color; you can then easily replace any color whenever it runs out. Some inkjet manufacturers also require you to use specially treated paper for printing high-quality images and documents. Such paper uses a moderate to high gloss coating formulated to absorb colored inks, which prevents clumping (the tendency for water-based inks to collect in certain areas where colors blend, causing muddiness or dried ink blots) or banding (where the print output has a striped pattern of extraneous lines on the printed page.) Consult your printer's documentation for recommended papers.

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