Linux Storage Management

Storage Management in Linux

Explore and Identify Block Devices

  • Check block device info: blkid
  • Show all block devices: lsblk
  • Get I/O information: blkid -i /dev/sdc1

Create and Modify Partitions

Partitioning Tools:

  • parted
  • fdisk
  • gparted
  • cfdisk

Create, Modify, and Mount File Systems

Common File Systems in Linux:

  • ext2 (standard)
  • ext3 (journaling support)
  • ext4 (supports large files)
  • xfs (developed by Sun)
  • btrfs (B-tree file system)
  • FAT32 (compatible with Windows and macOS)

Create a File System:

mkfs.ext4 /dev/sdc1

Mounting a File System:

mkdir /mnt/storage
mount /dev/sdc1 /mnt/storage

Verify and Review:

tune2fs -l /dev/sdc1

Unmounting a File System:

umount /mnt/storage

Create and Mount an Encrypted Partition

Encryption Tools:

  • dm-crypt
  • LUKS (Linux Unified Key Setup)
  • Available via the cryptsetup package

Encrypt a Partition:

cryptsetup luksFormat /dev/sdc2

Decrypt a Partition:

cryptsetup open /dev/sdc2 secret

Close an Encrypted Partition:

cryptsetup close secret

Configure Disk Mounting

  • View mount information: /etc/fstab
  • Mount all file systems from fstab: mount -a
  • Check mounted filesystems: df -h

Mount Volumes on Demand

Install Autofs:

sudo apt install autofs

Check Autofs Status:

sudo systemctl status autofs

Autofs Configuration File:

/etc/auto.master

Reconfigure Swap Space

Swap Basics:

  • When RAM is low, pages of memory move to disk
  • Swap space can be a partition or a file
  • 2x RAM if <2GB, at least 4GB if >2GB

Check Swap Usage:

cat /proc/swaps

Create a New Swap File:

swapoff /dev/sda5

dd if=/dev/zero of=/var/swapfile bs=1G count=8
chmod 600 /var/swapfile
mkswap /var/swapfile
swapon /var/swapfile

Persist Swap in /etc/fstab

Create Redundant Storage with RAID

RAID Levels:

  • RAID 0 - Striped volume (performance)
  • RAID 1 - Mirrored volume (redundancy)
  • RAID 5 - Distributed parity (3+ disks)
  • RAID 6 - Dual parity (4+ disks)

Configure RAID with mdadm:

sudo apt install mdadm
mdadm --create --level=1 --raid-devices=2 /dev/md0 /dev/sdb1 /dev/sdb2

Check RAID Status:

mdadm --detail /dev/md0

Add a File System:

mkfs.ext4 /dev/md0
mkdir /mnt/myraid
mount /dev/md0 /mnt/myraid

Manage RAID Disks:

mdadm --fail /dev/md0 /dev/sdb1
mdadm --remove /dev/md0 /dev/sdb1
mdadm --add /dev/md0 /dev/sdb3

Stop and Remove RAID:

umount /mnt/myraid
mdadm --stop /dev/md0
mdadm --remove /dev/md0
mdadm --zero-superblock /dev/sdb1 /dev/sdb2 /dev/sdb3

Logical Volume Management (LVM)

Install LVM Tools:

sudo apt install lvm2

Create a Physical Volume:

pvcreate /dev/sdb1
pvdisplay

Create a Volume Group:

vgcreate my_group /dev/sdb1
vgdisplay

Create a Logical Volume:

lvcreate -L 100G -n my_volume my_group
lvdisplay

Extend a Volume Group:

pvcreate /dev/sdc1
vgextend my_group /dev/sdc1
lvextend -l+100%FREE /dev/my_group/my_volume
resize2fs /dev/my_group/my_volume

Disk Quotas

Install Quota Tools:

sudo apt install quota

Enable Quotas:

quotacheck -c /mnt/storage
quotaon -pa
quotaon /mnt/storage

Set User Quota:

edquota username

Conclusion

This guide covers Linux storage management, including partitioning, file systems, RAID, LVM, encryption, and quotas. Understanding these concepts ensures efficient and secure storage management on Linux systems.