GNU/Linux storage

James Carter is a world-class Detroit-based saxophonist by day, and a RHEL Sysadmin by night. He wants to master storage on GNU/Linux systems. Please answer the following help James in his quest to master storage (please note that James prefers the term "Free Sofware" to "open-source":

1. What is the history of storage on GNU/Linux systems?
2. What are different storage media that are prevalent on GNU/Linux systems?
3. What are the most popular Free Software packages for storage managment on GNU/Linux?
4. Please give several examples of storage-related GNU/Linux commands, and fully explain each command.

1. History of Storage on GNU/Linux Systems

GNU/Linux has had a rich history in terms of storage solutions. In the initial stages, GNU/Linux adopted the traditional UNIX file systems like ext (Extended Filesystem) and xfs. Over time, the ext filesystem evolved through various versions, leading to ext4, which is widely used today. Linux also adopted networked filesystems such as NFS (Network File System) for sharing files over the network.

Logical Volume Management (LVM) became a significant advancement in GNU/Linux storage, allowing for flexible disk management. LVM allows the creation of logical volumes that can span multiple physical disks, permitting easier and more flexible disk space allocation and management.

In recent years, Btrfs (B-tree FS) and ZFS (originally from Solaris) have started gaining popularity, allowing for features such as snapshots and increased data integrity.

2. Different Storage Media Prevalent on GNU/Linux Systems

• Hard Disk Drives (HDDs): Traditional spinning disk drives which are widely used for mass storage.

• Solid-State Drives (SSDs): Faster than HDDs and used for high-performance requirements.

• Network Attached Storage (NAS): Devices connected to the network allowing for centralized storage accessible over the network.

• USB Drives: Portable storage devices that can be easily connected via USB ports.

• Optical Drives (CD/DVD): Used less frequently nowadays, but still supported.

• Cloud Storage: Interfaces to interact with cloud-based storage solutions such as AWS S3 or Azure Blob Storage.

3. Popular Free Software Packages for Storage Management on GNU/Linux

• LVM (Logical Volume Manager): Allows for the management of disk space with flexibility, facilitating the resizing of disk space and the management of multiple disks.

• mdadm: A tool for managing software RAID arrays.

• Samba: Allows GNU/Linux to interact with Windows network shares and vice versa.

• NFS (Network File System): Allows sharing of directories and files with others over a network.

• Btrfs tools: Tools to manage Btrfs filesystems, which support snapshots, pooling, and other advanced features.

• ZFS on Linux (ZoL): Allows the usage of the ZFS filesystem on Linux, bringing features such as data integrity and storage pooling.

4. Examples of Storage-Related GNU/Linux Commands

• lsblk: Lists information about all available block devices.

  lsblk
  • It displays the storage devices, their sizes, and mount points in a tree-like structure.

• df: Shows the amount of disk space used and available on the filesystem.

  df -h
  • The -h option makes the output human-readable, showing sizes in GB, MB, etc.

• mount: Mounts filesystems or storage devices to a specific directory.

  mount /dev/sda1 /mnt/mydrive
  • This command mounts the device /dev/sda1 to the directory /mnt/mydrive.

• umount: Unmounts filesystems or storage devices.

  umount /mnt/mydrive
  • This command unmounts the device mounted on the directory /mnt/mydrive.

• fdisk: A command-line utility to view and manage disk partitions.

  sudo fdisk /dev/sda
  • It allows you to create, delete, or modify partitions on a disk.

• mkfs: Creates a filesystem on a partition or storage device.

  mkfs.ext4 /dev/sda1
  • This command formats the /dev/sda1 partition as an ext4 filesystem.

These commands and tools, coupled with a strong understanding of GNU/Linux storage fundamentals, would significantly aid James Carter in mastering storage on GNU/Linux systems, aligning with his preference for Free Software principles.