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Oracle® Linux 6

Administrator's Solutions Guide

Oracle Legal Notices
Oracle Documentation License


March 2021

Table of Contents

1 The Unbreakable Enterprise Kernel
1.1 About the Unbreakable Enterprise Kernel
1.1.1 About UEK Release 1
1.1.2 About UEK Release 2
1.1.3 About UEK Release 3
1.1.4 About UEK Release 4
1.2 Obtaining and Installing the UEK Packages
1.3 For More Information About the UEK
2 Yum
2.1 About Yum
2.2 About ULN
2.3 Yum Configuration
2.3.1 Configuring Use of a Proxy Server
2.3.2 Yum Repository Configuration
2.3.3 Downloading the Oracle Linux Yum Server Repository Files
2.3.4 Using Yum Utilities to Manage Configuration
2.4 Using Yum from the Command Line
2.5 Yum Groups
2.6 Installing and Using the Yum Security Plugin
2.7 Switching CentOS or Scientific Linux Systems to Use the Oracle Linux Yum Server
2.8 Creating and Using a Local ULN Mirror
2.9 Creating a Local Yum Repository Using an ISO Image
2.10 Setting up a Local Yum Server Using an ISO Image
2.11 For More Information About Yum
3 Ksplice
3.1 Overview of Oracle Ksplice
3.1.1 Supported Kernels
3.1.2 About Ksplice Updates
3.1.3 Patching and Updating Your System
3.2 About the Ksplice Client Software
3.2.1 About the Ksplice Enhanced Client
3.2.2 About the Ksplice Uptrack Client
3.3 Choosing a Ksplice Client
3.4 Preparing to Use Oracle Ksplice
4 The Btrfs File System
4.1 About the Btrfs File System
4.2 Creating a Btrfs File System
4.3 Modifying a Btrfs File System
4.4 Compressing and Defragmenting a Btrfs File System
4.5 Resizing a Btrfs File System
4.6 Creating Subvolumes and Snapshots
4.6.1 Cloning Virtual Machine Images and Linux Containers
4.7 Using the Send/Receive Feature
4.7.1 Using Send/Receive to Implement Incremental Backups
4.8 Using Quota Groups
4.9 Replacing Devices on a Live File System
4.10 Creating Snapshots of Files
4.11 Converting an Ext2, Ext3, or Ext4 File System to a Btrfs File System
4.11.1 Converting a Non-root File System
4.11.2 Converting the root File System
4.11.3 Mounting the Image of the Original File System
4.11.4 Deleting the Snapshot of the Original File System
4.11.5 Recovering an Original Non-root File System
4.12 Installing a Btrfs root File System
4.12.1 Setting up a New NFS Server
4.12.2 Configuring an Existing NFS Server
4.12.3 Setting up a New HTTP Server
4.12.4 Configuring an Existing HTTP Server
4.12.5 Setting up a Network Installation Server
4.12.6 Installing from a Network Installation Server
4.12.7 About the Installation root File System
4.12.8 Creating Snapshots of the root File System
4.12.9 Mounting Alternate Snapshots as the root File System
4.12.10 Deleting Snapshots of the root File System
5 The XFS File System
5.1 About the XFS File System
5.1.1 About External XFS Journals
5.1.2 About XFS Write Barriers
5.1.3 About Lazy Counters
5.2 Installing the XFS Packages
5.3 Creating an XFS File System
5.4 Modifying an XFS File System
5.5 Growing an XFS File System
5.6 Freezing and Unfreezing an XFS File System
5.7 Setting Quotas on an XFS File System
5.7.1 Setting Project Quotas
5.8 Backing up and Restoring XFS File Systems
5.9 Defragmenting an XFS File System
5.10 Checking and Repairing an XFS File System
6 Oracle Cluster File System Version 2
6.1 About OCFS2
6.2 Installing and Configuring OCFS2
6.2.1 Preparing a Cluster for OCFS2
6.2.2 Configuring the Firewall
6.2.3 Configuring the Cluster Software
6.2.4 Creating the Configuration File for the Cluster Stack
6.2.5 Configuring the Cluster Stack
6.2.6 Configuring the Kernel for Cluster Operation
6.2.7 Starting and Stopping the Cluster Stack
6.2.8 Creating OCFS2 volumes
6.2.9 Mounting OCFS2 Volumes
6.2.10 Querying and Changing Volume Parameters
6.3 Troubleshooting OCFS2
6.3.1 Recommended Tools for Debugging
6.3.2 Mounting the debugfs File System
6.3.3 Configuring OCFS2 Tracing
6.3.4 Debugging File System Locks
6.3.5 Configuring the Behavior of Fenced Nodes
6.4 Use Cases for OCFS2
6.4.1 Load Balancing
6.4.2 Oracle Real Application Cluster (RAC)
6.4.3 Oracle Databases
6.5 For More Information About OCFS2
7 Control Groups
7.1 About cgroups
7.2 Subsystems
7.2.1 blkio Parameters
7.2.2 cpu Parameters
7.2.3 cpuacct Parameters
7.2.4 cpuset Parameters
7.2.5 devices Parameters
7.2.6 freezer Parameter
7.2.7 memory Parameters
7.2.8 net_cls Parameter
7.3 Enabling the cgconfig Service
7.4 Enabling PAM to Work with cgroup Rules
7.5 Restarting the cgconfig Service
7.6 About the cgroups Configuration File
7.7 About the cgroup Rules Configuration File
7.8 Displaying and Setting Subsystem Parameters
7.9 Use Cases for cgroups
7.9.1 Pinning Processes to CPU Cores
7.9.2 Controlling CPU and Memory Usage
7.9.3 Restricting Access to Devices
7.9.4 Throttling I/O Bandwidth
8 Linux Containers
8.1 About Linux Containers
8.1.1 Supported Oracle Linux Container Versions
8.2 Configuring Operating System Containers
8.2.1 Installing and Configuring the Software
8.2.2 Setting up the File System for the Containers
8.2.3 Creating and Starting a Container
8.2.4 About the lxc-oracle Template Script
8.2.5 About Veth and Macvlan
8.2.6 Modifying a Container to Use Macvlan
8.3 Logging in to Containers
8.4 Creating Additional Containers
8.5 Monitoring and Shutting Down Containers
8.6 Starting a Command Inside a Running Container
8.7 Controlling Container Resources
8.8 Configuring ulimit Settings for an Oracle Linux Container
8.9 Configuring Kernel Parameter Settings for Oracle Linux Containers
8.10 Deleting Containers
8.11 Running Application Containers
8.12 For More Information About Linux Containers
9 HugePages
9.1 About HugePages
9.2 Configuring HugePages for Oracle Database
9.3 For More Information About HugePages
10 Using kexec for Fast Rebooting
10.1 About kexec
10.2 Setting up Fast Reboots of the Current Kernel
10.3 Controlling Fast Reboots
10.4 For More Information About kexec
11 DTrace
11.1 About DTrace
11.2 Installing and Configuring DTrace
11.2.1 Changing the Mode of the DTrace Helper Device
11.2.2 Loading DTrace Kernel Modules
11.3 Differences Between DTrace on Oracle Linux and Oracle Solaris
11.4 Calling DTrace from the Command Line
11.5 About Programming for DTrace
11.6 Introducing the D Programming Language
11.6.1 Probe Clauses
11.6.2 Pragmas
11.6.3 Global Variables
11.6.4 Predicates
11.6.5 Scalar Arrays and Associative Arrays
11.6.6 Pointers and External Variables
11.6.7 Address Spaces
11.6.8 Thread-local Variables
11.6.9 Speculations
11.6.10 Aggregations
11.7 DTrace Command Examples
11.8 Tracing User-Space Applications
11.8.1 Examining the Stack Trace of a User-Space Application
11.9 For More Information About DTrace
12 Support Diagnostic Tools
12.1 About sosreport
12.1.1 Configuring and Using sosreport
12.2 About Kdump
12.2.1 Configuring and Using Kdump
12.2.2 Files Used by Kdump
12.3 About OSWatcher Black Box
12.3.1 Installing OSWbb
12.3.2 Running OSWbb
12.4 For More Information About the Diagnostic Tools