362.3 Clustered File Systems (weight: 4)

Tech Tutorial: 362.3 Clustered File Systems (weight: 4) #

Introduction #

Clustered file systems are an essential part of managing data in an environment where multiple computers (nodes) need to access the same data simultaneously. Unlike traditional file systems, clustered file systems are designed to provide consistency and reliability across a network of computers. This tutorial will guide you through the understanding and setup of clustered file systems, specifically focusing on commonly used technologies and utilities in Linux environments.

Exam Objective: #

The objective of this section is to understand, configure, and manage clustered file systems in a Linux environment. This includes the ability to work with various utilities and command-line tools associated with clustered file systems.

Key Knowledge Areas: #

  • Understanding of GFS2 and OCFS2
  • Configuration and basic usage of clustered file systems
  • Awareness of the distributed file systems like Ceph and GlusterFS

Utilities: #

  • mkfs.gfs2
  • mkfs.ocfs2
  • mount
  • fsck
  • ceph
  • gluster

Step-by-Step Guide #

Each subsection will cover the configuration and usage of different clustered file systems, along with practical examples.

1. GFS2 (Global File System 2) #

GFS2 is a shared-disk file system for Linux computer clusters.

Installation: #

sudo yum install -y gfs2-utils

Creating a GFS2 file system: #

First, you must have a shared storage device visible from all nodes, like an iSCSI device.

# Assuming /dev/sdb is the shared storage device
sudo mkfs.gfs2 -p lock_nolock -j 2 /dev/sdb

Here, -j 2 specifies the number of journals.

Mounting the GFS2 file system: #

sudo mkdir /mnt/gfs2
sudo mount -t gfs2 /dev/sdb /mnt/gfs2

2. OCFS2 (Oracle Cluster File System) #

OCFS2 is another shared disk file system designed for use in clusters.

Installation: #

sudo apt-get install ocfs2-tools

Creating an OCFS2 file system: #

sudo mkfs.ocfs2 -N 4 /dev/sdb

Here, -N 4 specifies the number of nodes.

Mounting the OCFS2 file system: #

sudo mkdir /mnt/ocfs2
sudo mount -t ocfs2 /dev/sdb /mnt/ocfs2

3. Checking and Repairing GFS2 and OCFS2 #

Use fsck to check and repair GFS2 or OCFS2 file systems.

sudo fsck.gfs2 /dev/sdb
sudo fsck.ocfs2 /dev/sdb

4. Distributed File Systems: Ceph and GlusterFS #

These systems allow for the setup of highly scalable and redundant storage solutions.

Basic Ceph Deployment: #

sudo apt install ceph
ceph-deploy new node1 node2 node3
ceph-deploy mon create-initial

Basic GlusterFS Setup: #

sudo apt-get install glusterfs-server
sudo gluster peer probe node1
sudo gluster peer probe node2
sudo gluster volume create gv0 replica 2 node1:/data node2:/data
sudo gluster volume start gv0

Mounting a GlusterFS Volume: #

sudo mount -t glusterfs node1:/gv0 /mnt/glusterfs

Conclusion #

In this tutorial, we covered the basics of setting up and managing clustered file systems in Linux, focusing on GFS2 and OCFS2. We also touched upon distributed file systems like Ceph and GlusterFS, which are crucial for building scalable, high-availability storage solutions. The commands and configurations provided here should serve as a solid foundation for further exploration and production deployment of clustered file systems.

Remember, each environment is different, and specific configurations may vary based on your particular hardware and network setup. Always refer to the official documentation for detailed information and best practices.