mtpti5iD/redhat-docs_dataset huggingface dataset:
17.9. Troubleshooting issues in the Red Hat Gluster Storage Trusted Storage Pool 17.9.1. Troubleshooting a network issue in the Red Hat Gluster Storage Trusted Storage Pool When enabling the network components to communicate with Jumbo frames in a Red Hat Gluster Storage Trusted Storage Pool, ensure that all the network components such as switches, Red Hat Gluster Storage nodes etc are configured properly. Verify the network configuration by running the ping from one Red Hat Gluster Storage node to another. If the nodes in the Red Hat Gluster Storage Trusted Storage Pool or any other network components are not configured to fully support Jumbo frames, the ping command times out and displays the following error:

Commands:
ping -s 1600 '-Mdo'IP_ADDRESS local error: Message too long, mtu=1500
Chapter 15. Red Hat Enterprise Linux System Roles Powered by Ansible Selected roles of Red Hat Enterprise Linux System Roles are now fully supported Red Hat Enterprise Linux System Roles provides a configuration interface for Red Hat Enterprise Linux subsystems, which makes system configuration easier through the inclusion of Ansible Roles. This interface enables managing system configurations across multiple versions of Red Hat Enterprise Linux, as well as adopting new major releases. The interface currently consists of the following roles: selinux kdump network timesync postfix Red Hat Enterprise Linux System Roles have been available since Red Hat Enterprise Linux 7.4 as a Technology Preview. With this update, the selinux , kdump , network , and timesync roles are fully supported. The postfix role continues to be available as a Technology Preview. Since Red Hat Enterprise Linux 7.4, the Red Hat Enterprise Linux System Roles packages have been distributed through the Extras channel. For details regarding Red Hat Enterprise Linux System Roles, see https://access.redhat.com/articles/3050101 . Selected roles of the rhel-system-roles package have received multiple bug fixes and significant enhancements to improve interface consistency, usability, and conformance to Ansible best practices. Note that for the timesync , kdump , and selinux roles, the changes are not backward compatible and it is necessary to update playbooks that use them. For more information, see https://access.redhat.com/articles/3561071 . (BZ#1479381)

Commands:
Chapter 116. KafkaUserTemplate schema reference Used in: KafkaUserSpec Full list of KafkaUserTemplate schema properties Specify additional labels and annotations for the secret created by the User Operator. An example showing the KafkaUserTemplate apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaUser metadata: name: my-user labels: strimzi.io/cluster: my-cluster spec: authentication: type: tls template: secret: metadata: labels: label1: value1 annotations: anno1: value1 # ... 116.1. KafkaUserTemplate schema properties Property Property type Description secret ResourceTemplate Template for KafkaUser resources. The template allows users to specify how the Secret with password or TLS certificates is generated.

Commands:
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaUser metadata: name: my-user labels: strimzi.io/cluster: my-cluster spec: authentication: type: tls template: secret: metadata: labels: label1: value1 annotations: anno1: value1 #
A.3. Install and Configure keepalived Perform the following procedure on your two HAProxy nodes: Install keepalived. Configure keepalived. In the following configuration, there is a script to check the HAProxy processes. The instance uses eth0 as the network interface and configures haproxy as the master server and haproxy2 as the backup server. It also assigns a virtual IP address of 192.168.0.100. Enable and start keepalived.

Commands:
yum install -y keepalived
vim /etc/keepalived/keepalived.conf
vrrp_script chk_haproxy { script "killall -0 haproxy" # check the haproxy process interval 2 # every 2 seconds weight 2 # add 2 points if OK } vrrp_instance VI_1 { interface eth0 # interface to monitor state MASTER # MASTER on haproxy, BACKUP on haproxy2 virtual_router_id 51 priority 101 # 101 on haproxy, 100 on haproxy2 virtual_ipaddress { 192.168.0.100 # virtual ip address } track_script { chk_haproxy } }
systemctl enable keepalived systemctl start keepalived
2.6. Software Collection Scriptlets The Software Collection scriptlets are simple shell scripts that change the current system environment so that the group of packages in the Software Collection is preferred over the corresponding group of conventional packages installed on the system. To utilize the Software Collection scriptlets, use the scl tool that is part of the scl-utils package. For more information on scl , refer to Section 1.6, "Enabling a Software Collection" . A single Software Collection can include multiple Software Collection scriptlets. These scriptlets are located in the /opt/provider/software_collection/ directory in your Software Collection package. If you only need to distribute a single scriptlet in your Software Collection, it is highly recommended that you use enable as the name for that scriptlet. When the user runs a command in the Software Collection environment by executing scl enable software_collection command , the /opt/provider/software_collection/enable scriptlet is then used to update search paths, and so on. Note that Software Collection scriptlets can only set the system environment in a subshell that is created by running the scl enable command. The subshell is only active for the time the command is being performed.

Commands:
7.2. Templates To create a template, an administrator creates and customizes a virtual machine. Desired packages are installed, customized configurations are applied, the virtual machine is prepared for its intended purpose in order to minimize the changes that must be made to it after deployment. An optional but recommended step before creating a template from a virtual machine is generalization. Generalization is used to remove details like system user names, passwords, and timezone information that will change upon deployment. Generalization does not affect customized configurations. Generalization of Windows and Linux guests in the Red Hat Virtualization environment is discussed further in Templates in the Virtual Machine Management Guide . Red Hat Enterprise Linux guests are generalized using sys-unconfig . Windows guests are generalized using sys-prep . When the virtual machine that provides the basis for a template is satisfactorily configured, generalized if desired, and stopped, an administrator can create a template from the virtual machine. Creating a template from a virtual machine causes a read-only copy of the specially configured virtual disk to be created. The read-only image forms the backing image for all subsequently created virtual machines that are based on that template. In other words, a template is essentially a customized read-only virtual disk with an associated virtual hardware configuration. The hardware can be changed in virtual machines created from a template, for instance, provisioning two gigabytes of RAM for a virtual machine created from a template that has one gigabyte of RAM. The template virtual disk, however, cannot be changed as doing so would result in changes for all virtual machines based on the template. When a template has been created, it can be used as the basis for multiple virtual machines. Virtual machines are created from a given template using a Thin provisioning method or a Clone provisioning method. Virtual machines that are cloned from templates take a complete writable copy of the template base image, sacrificing the space savings of the thin creation method in exchange for no longer depending on the presence of the template. Virtual machines that are created from a template using the thin method use the read-only image from the template as a base image, requiring that the template and all virtual machines created from it be stored on the same storage domain. Changes to data and newly generated data are stored in a copy-on-write image. Each virtual machine based on a template uses the same base read-only image, as well as a copy-on-write image that is unique to the virtual machine. This provides storage savings by limiting the number of times identical data is kept in storage. Furthermore, frequent use of the read-only backing image can cause the data being accessed to be cached, resulting in a net performance increase.

Commands:
Chapter 46. limits This chapter describes the commands under the limits command. 46.1. limits show Show compute and block storage limits Usage: Table 46.1. Command arguments Value Summary -h, --help Show this help message and exit --absolute Show absolute limits --rate Show rate limits --reserved Include reservations count [only valid with --absolute] --project <project> Show limits for a specific project (name or id) [only valid with --absolute] --domain <domain> Domain the project belongs to (name or id) [only valid with --absolute] Table 46.2. Output formatter options Value Summary -f {csv,json,table,value,yaml}, --format {csv,json,table,value,yaml} The output format, defaults to table -c COLUMN, --column COLUMN Specify the column(s) to include, can be repeated --sort-column SORT_COLUMN Specify the column(s) to sort the data (columns specified first have a priority, non-existing columns are ignored), can be repeated Table 46.3. CSV formatter options Value Summary --quote {all,minimal,none,nonnumeric} When to include quotes, defaults to nonnumeric Table 46.4. JSON formatter options Value Summary --noindent Whether to disable indenting the json Table 46.5. 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 limits show [-h] [-f {csv,json,table,value,yaml}] [-c COLUMN] [--quote {all,minimal,none,nonnumeric}] [--noindent] [--max-width <integer>] [--fit-width] [--print-empty] [--sort-column SORT_COLUMN] (--absolute | --rate) [--reserved] [--project <project>] [--domain <domain>]
5.3.12. Combining Volume Groups To combine two volume groups into a single volume group, use the vgmerge command. You can merge an inactive "source" volume with an active or an inactive "destination" volume if the physical extent sizes of the volume are equal and the physical and logical volume summaries of both volume groups fit into the destination volume groups limits. The following command merges the inactive volume group my_vg into the active or inactive volume group databases giving verbose runtime information.

Commands:
vgmerge -v databases my_vg
3.2. Guest Security Recommended Practices All of the recommended practices for securing a Red Hat Enterprise Linux system documented in the Red Hat Enterprise Linux Security Guide apply to conventional, non-virtualized systems as well as systems installed as a virtualized guest. However, there are a few security practices which are of critical importance when running guests in a virtualized environment: With all management of the guest likely taking place remotely, ensure that the management of the system takes place only over secured network channels. Tools such as SSH and network protocols such as TLS or SSL provide both authentication and data encryption to ensure that only approved administrators can manage the system remotely. Some virtualization technologies use special guest agents or drivers to enable some virtualization specific features. Ensure that these agents and applications are secured using the standard Red Hat Enterprise Linux security features, such as SELinux. In virtualized environments, a greater risk exists of sensitive data being accessed outside the protection boundaries of the guest system. Protect stored sensitive data using encryption tools such as dm-crypt and GnuPG ; although special care needs to be taken to ensure the confidentiality of the encryption keys. Note Using page deduplication technology such as Kernel Same-page Merging (KSM) may introduce side channels that could potentially be used to leak information across guests. In situations where this is a concern, KSM can be disabled either globally or on a per-guest basis. For more information about KSM, see the Red Hat Enterprise Linux 7 Virtualization Tuning and Optimization Guide .

Commands:
15.2.5. Freshening Freshening a package is similar to upgrading one. Type the following command at a shell prompt: RPM's freshen option checks the versions of the packages specified on the command line against the versions of packages that have already been installed on your system. When a newer version of an already-installed package is processed by RPM's freshen option, it is upgraded to the newer version. However, RPM's freshen option does not install a package if no previously-installed package of the same name exists. This differs from RPM's upgrade option, as an upgrade does install packages, whether or not an older version of the package was already installed. RPM's freshen option works for single packages or package groups. If you have just downloaded a large number of different packages, and you only want to upgrade those packages that are already installed on your system, freshening does the job. If you use freshening, you do not have to delete any unwanted packages from the group that you downloaded before using RPM. In this case, issue the following command: RPM automatically upgrades only those packages that are already installed.

Commands:
-Fvh foo-1.2-1.i386.rpm
-Fvh *.rpm
Chapter 1. User and group APIs 1.1. Group [user.openshift.io/v1] Description Group represents a referenceable set of Users Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer). Type object 1.2. Identity [user.openshift.io/v1] Description Identity records a successful authentication of a user with an identity provider. The information about the source of authentication is stored on the identity, and the identity is then associated with a single user object. Multiple identities can reference a single user. Information retrieved from the authentication provider is stored in the extra field using a schema determined by the provider. Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer). Type object 1.3. UserIdentityMapping [user.openshift.io/v1] Description UserIdentityMapping maps a user to an identity Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer). Type object 1.4. User [user.openshift.io/v1] Description Upon log in, every user of the system receives a User and Identity resource. Administrators may directly manipulate the attributes of the users for their own tracking, or set groups via the API. The user name is unique and is chosen based on the value provided by the identity provider - if a user already exists with the incoming name, the user name may have a number appended to it depending on the configuration of the system. Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer). Type object

Commands:
probe::netfilter.ip.forward Name probe::netfilter.ip.forward - Called on an incoming IP packet addressed to some other computer Synopsis netfilter.ip.forward Values saddr A string representing the source IP address sport TCP or UDP source port (ipv4 only) daddr A string representing the destination IP address pf Protocol family -- either " ipv4 " or " ipv6 " indev Address of net_device representing input device, 0 if unknown nf_drop Constant used to signify a 'drop' verdict nf_queue Constant used to signify a 'queue' verdict dport TCP or UDP destination port (ipv4 only) iphdr Address of IP header fin TCP FIN flag (if protocol is TCP; ipv4 only) ack TCP ACK flag (if protocol is TCP; ipv4 only) syn TCP SYN flag (if protocol is TCP; ipv4 only) ipproto_udp Constant used to signify that the packet protocol is UDP outdev_name Name of network device packet will be routed to (if known) nf_accept Constant used to signify an 'accept' verdict rst TCP RST flag (if protocol is TCP; ipv4 only) protocol Packet protocol from driver (ipv4 only) nf_stop Constant used to signify a 'stop' verdict length The length of the packet buffer contents, in bytes nf_stolen Constant used to signify a 'stolen' verdict urg TCP URG flag (if protocol is TCP; ipv4 only) psh TCP PSH flag (if protocol is TCP; ipv4 only) ipproto_tcp Constant used to signify that the packet protocol is TCP indev_name Name of network device packet was received on (if known) family IP address family outdev Address of net_device representing output device, 0 if unknown nf_repeat Constant used to signify a 'repeat' verdict

Commands:
Chapter 9. Redundant Array of Independent Disks (RAID) 9.1. What is RAID? The basic idea behind RAID is to combine multiple small, inexpensive disk drives into an array to accomplish performance or redundancy goals not attainable with one large and expensive drive. This array of drives appears to the computer as a single logical storage unit or drive. RAID is a method in which information is spread across several disks. RAID uses techniques such as disk striping (RAID Level 0), disk mirroring (RAID level 1), and disk striping with parity (RAID Level 5) to achieve redundancy, lower latency and/or to increase bandwidth for reading or writing to disks, and to maximize the ability to recover from hard disk crashes. The underlying concept of RAID is that data may be distributed across each drive in the array in a consistent manner. To do this, the data must first be broken into consistently-sized chunks (often 32K or 64K in size, although different sizes can be used). Each chunk is then written to a hard drive in the RAID array according to the RAID level used. When the data is to be read, the process is reversed, giving the illusion that the multiple drives in the array are actually one large drive.

Commands:
4.161. lohit-malayalam-fonts 4.161.1. RHEA-2011:1136 - lohit-malayalam-fonts enhancement update An updated lohit-malayalam-fonts package which adds one enhancement is now available for Red Hat Enterprise Linux 6. The lohit-malayalam-fonts package provides a free Malayalam TrueType/OpenType font. Enhancement BZ# 691290 Unicode 6.0, the most recent major version of the Unicode standard, introduces the Indian Rupee Sign (U+20B9), the new official Indian currency symbol. With this update, the lohit-malayalam-fonts package now includes a glyph for this new character. All users requiring the Indian rupee sign should install this updated package, which adds this enhancement.

Commands:
probe::ipmib.ReasmTimeout Name probe::ipmib.ReasmTimeout - Count Reassembly Timeouts Synopsis ipmib.ReasmTimeout 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 ReasmTimeout (equivalent to SNMP's MIB IPSTATS_MIB_REASMTIMEOUT)

Commands:
3.9. net_prio The Network Priority ( net_prio ) subsystem provides a way to dynamically set the priority of network traffic per each network interface for applications within various cgroups. A network's priority is a number assigned to network traffic and used internally by the system and network devices. Network priority is used to differentiate packets that are sent, queued, or dropped. The tc command may be used to set a network's priority (setting the network priority via the tc command is outside the scope of this guide; for more information, refer to the tc man page). Typically, an application sets the priority of its traffic via the SO_PRIORITY socket option. However, applications are often not coded to set the priority value, or the application's traffic is site-specific and does not provide a defined priority. Using the net_prio subsystem in a cgroup allows the administrator to assign a process to a specific cgroup which defines the priority of outgoing traffic on a given network interface. The following tunable parameters are available for net_prio : net_prio.prioidx a read-only file which contains a unique integer value that the kernel uses as an internal representation of this cgroup. net_prio.ifpriomap contains a map of priorities assigned to traffic originating from processes in this group and leaving the system on various interfaces. This map is represented by a list of pairs in the form <network_interface> <priority> : Contents of the net_prio.ifpriomap file can be modified by echoing a string into the file using the above format, for example: The above command forces any traffic originating from processes belonging to the iscsi net_prio cgroup, and with traffic outgoing on the eth0 network interface, to have the priority set to the value of 5 . The parent cgroup also has a writable net_prio.ifpriomap file that can be used to set a system default priority.

Commands:
~]# cat /cgroup/net_prio/iscsi/net_prio.ifpriomap eth0 5 eth1 4 eth2 6
~]# echo "eth0 5" > /cgroup/net_prio/iscsi/net_prio.ifpriomap
Chapter 15. Red Hat Software Collections Red Hat Software Collections is a Red Hat content set that provides a set of dynamic programming languages, database servers, and related packages that you can install and use on all supported releases of Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7 on AMD64 and Intel 64 architectures. Red Hat Developer Toolset is included as a separate Software Collection. Red Hat Developer Toolset is designed for developers working on the Red Hat Enterprise Linux platform. It provides current versions of the GNU Compiler Collection, GNU Debugger, and other development, debugging, and performance monitoring tools. Since Red Hat Software Collections 2.3, the Eclipse development platform is provided as a separate Software Collection. Dynamic languages, database servers, and other tools distributed with Red Hat Software Collections do not replace the default system tools provided with Red Hat Enterprise Linux, nor are they used in preference to these tools. Red Hat Software Collections uses an alternative packaging mechanism based on the scl utility to provide a parallel set of packages. This set enables optional use of alternative package versions on Red Hat Enterprise Linux. By using the scl utility, users can choose which package version they want to run at any time. Important Red Hat Software Collections has a shorter life cycle and support term than Red Hat Enterprise Linux. For more information, see the Red Hat Software Collections Product Life Cycle . See the Red Hat Software Collections documentation for the components included in the set, system requirements, known problems, usage, and specifics of individual Software Collections. See the Red Hat Developer Toolset documentation for more information about the components included in this Software Collection, installation, usage, known problems, and more.

Commands:
2.2.6.3. User Accounts Because FTP transmits unencrypted user names and passwords over insecure networks for authentication, it is a good idea to deny system users access to the server from their user accounts. To disable all user accounts in vsftpd , add the following directive to /etc/vsftpd/vsftpd.conf : 2.2.6.3.1. Restricting User Accounts To disable FTP access for specific accounts or specific groups of accounts, such as the root user and those with sudo privileges, the easiest way is to use a PAM list file as described in Section 2.1.9.2, "Disallowing Root Access" . The PAM configuration file for vsftpd is /etc/pam.d/vsftpd . It is also possible to disable user accounts within each service directly. To disable specific user accounts in vsftpd , add the user name to /etc/vsftpd/ftpusers

Commands:
local_enable=NO