Domain 5: Storage Management (15%) and Domain 6: Service Configuration (20%)¶

Overview¶

This combined notes file covers storage management (partitioning, filesystems, LVM, RAID, swap) and service configuration (Apache, Nginx, NFS, Samba, DNS, databases). These two domains together represent 35% of the exam.

Disk Partitioning¶

Viewing Storage Devices¶

lsblk                             # list block devices (tree view)
lsblk -f                          # include filesystem info
fdisk -l                          # list all disks and partitions
blkid                             # show UUID and filesystem type
df -h                             # mounted filesystem usage

Partition Tables¶

MBR - Legacy, max 2TB disk, 4 primary partitions
GPT - Modern, no practical size limit, 128 partitions

fdisk (MBR) and gdisk (GPT)¶

fdisk /dev/sdb                    # MBR partitioning
# p=print, n=new, d=delete, t=type, w=write, q=quit

gdisk /dev/sdb                    # GPT partitioning
# Same interactive commands as fdisk

parted /dev/sdb                   # Both MBR and GPT
parted /dev/sdb mklabel gpt
parted /dev/sdb mkpart primary ext4 0% 50%

Filesystems¶

Creating and Managing¶

# Create filesystem
mkfs.ext4 /dev/sdb1               # ext4
mkfs.xfs /dev/sdb1                # XFS

# Mount
mount /dev/sdb1 /mnt              # temporary mount
mkdir -p /data                    # create mount point
mount /dev/sdb1 /data

# Persistent mount (/etc/fstab)
# UUID=abc123  /data  ext4  defaults  0  2
blkid /dev/sdb1                   # get UUID
mount -a                          # mount all in fstab (test before reboot!)

# Filesystem operations
umount /mnt                       # unmount
fsck /dev/sdb1                    # check (unmounted only!)
resize2fs /dev/sdb1               # resize ext4
xfs_growfs /mountpoint            # grow XFS (mounted, can only grow)
tune2fs -l /dev/sdb1              # ext4 info

/etc/fstab Format¶

# device         mountpoint  type  options    dump  pass
UUID=abc123      /data       ext4  defaults   0     2
/dev/md0         /mnt/raid   ext4  defaults   0     2
server:/share    /mnt/nfs    nfs   defaults   0     0
/swapfile        swap        swap  defaults   0     0

Logical Volume Management (LVM)¶

📖 LVM Documentation - LVM reference

LVM Architecture¶

Physical Volumes (PV) -> Volume Groups (VG) -> Logical Volumes (LV)

Complete LVM Workflow¶

# Step 1: Create Physical Volumes
pvcreate /dev/sdb1
pvcreate /dev/sdc1
pvdisplay                         # view details
pvs                               # brief list

# Step 2: Create Volume Group
vgcreate datavg /dev/sdb1 /dev/sdc1
vgdisplay
vgs

# Step 3: Create Logical Volume
lvcreate -L 10G -n datalv datavg          # fixed size
lvcreate -l 100%FREE -n datalv datavg     # all free space
lvdisplay
lvs

# Step 4: Create filesystem
mkfs.ext4 /dev/datavg/datalv

# Step 5: Mount
mkdir /data
mount /dev/datavg/datalv /data

# Step 6: Persist in fstab
echo "/dev/datavg/datalv /data ext4 defaults 0 2" >> /etc/fstab

Extending LVM¶

# Add new PV to VG
pvcreate /dev/sdd1
vgextend datavg /dev/sdd1

# Extend LV
lvextend -L +5G /dev/datavg/datalv          # add 5GB
lvextend -l +100%FREE /dev/datavg/datalv    # use all free space

# Resize filesystem AFTER extending LV
resize2fs /dev/datavg/datalv               # ext4
xfs_growfs /data                           # XFS (specify mount point)

# Combined extend + resize
lvextend -r -L +5G /dev/datavg/datalv      # -r resizes filesystem too

LVM Display Commands¶

pvs / pvdisplay                   # physical volumes
vgs / vgdisplay                   # volume groups
lvs / lvdisplay                   # logical volumes

RAID Configuration¶

RAID Levels¶

Level	Min Disks	Fault Tolerance	Capacity
RAID 0	2	None (striping)	All disks
RAID 1	2	1 disk (mirroring)	50%
RAID 5	3	1 disk (parity)	N-1 disks
RAID 6	4	2 disks	N-2 disks
RAID 10	4	1 per mirror	50%

mdadm¶

# Create RAID 1
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1

# Create RAID 5
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1

# Check status
mdadm --detail /dev/md0
cat /proc/mdstat

# Save config
mdadm --detail --scan >> /etc/mdadm/mdadm.conf
update-initramfs -u

# Use RAID device like a regular disk
mkfs.ext4 /dev/md0
mount /dev/md0 /mnt/raid

# Manage
mdadm --add /dev/md0 /dev/sde1           # add spare
mdadm --remove /dev/md0 /dev/sdc1        # remove failed disk

Swap Management¶

# Swap partition
mkswap /dev/sdb2
swapon /dev/sdb2

# Swap file
fallocate -l 1G /swapfile         # or: dd if=/dev/zero of=/swapfile bs=1M count=1024
chmod 600 /swapfile               # required!
mkswap /swapfile
swapon /swapfile

# Verify
swapon --show
free -h

# Persistent in fstab
# /swapfile swap swap defaults 0 0

Service Configuration¶

Apache Web Server¶

# Install and start
apt install apache2
systemctl enable --now apache2

# Key locations
/etc/apache2/apache2.conf         # main config
/etc/apache2/sites-available/     # virtual host configs
/etc/apache2/sites-enabled/       # enabled sites (symlinks)
/var/www/html/                     # default document root

Virtual Host¶

# /etc/apache2/sites-available/mysite.conf
<VirtualHost *:80>
    ServerName mysite.local
    DocumentRoot /var/www/mysite
    ErrorLog ${APACHE_LOG_DIR}/mysite-error.log
    CustomLog ${APACHE_LOG_DIR}/mysite-access.log combined
    <Directory /var/www/mysite>
        Require all granted
    </Directory>
</VirtualHost>

a2ensite mysite.conf              # enable site
a2dissite 000-default.conf        # disable default
a2enmod ssl                       # enable module
apache2ctl configtest             # test config
systemctl reload apache2          # apply changes

HTTPS with Self-Signed Certificate¶

a2enmod ssl
openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
  -keyout /etc/ssl/private/mysite.key \
  -out /etc/ssl/certs/mysite.crt
# Create SSL virtual host referencing cert and key
a2ensite mysite-ssl.conf
systemctl reload apache2

Nginx Web Server¶

apt install nginx
systemctl enable --now nginx

# Key locations
/etc/nginx/nginx.conf
/etc/nginx/sites-available/
/etc/nginx/sites-enabled/

Server Block¶

# /etc/nginx/sites-available/mysite
server {
    listen 80;
    server_name mysite.local;
    root /var/www/mysite;
    index index.html;
    location / {
        try_files $uri $uri/ =404;
    }
}

ln -s /etc/nginx/sites-available/mysite /etc/nginx/sites-enabled/
nginx -t                          # test config
systemctl reload nginx

NFS (Network File System)¶

# Server
apt install nfs-kernel-server

# /etc/exports
/exports/shared    192.168.1.0/24(rw,sync,no_subtree_check)
/exports/readonly  *(ro,sync)

exportfs -a                       # apply exports
exportfs -v                       # show exports
systemctl enable --now nfs-kernel-server

# Client
apt install nfs-common
mount server:/exports/shared /mnt/nfs
showmount -e server               # show available exports

# Persistent in fstab
# server:/exports/shared  /mnt/nfs  nfs  defaults  0  0

NFS Export Options¶

Option	Description
rw	Read-write access
ro	Read-only access
sync	Synchronous writes (safer)
async	Asynchronous writes (faster)
no_subtree_check	Disable subtree checking (recommended)
no_root_squash	Allow remote root access
root_squash	Map remote root to nobody (default)

apt install samba

# /etc/samba/smb.conf
[global]
    workgroup = WORKGROUP
    security = user

[shared]
    path = /srv/samba/shared
    browsable = yes
    writable = yes
    valid users = @smbusers
    create mask = 0660
    directory mask = 0770

# Create Samba user
useradd -m smbuser
smbpasswd -a smbuser

# Test and restart
testparm                          # validate config
systemctl enable --now smbd

# Client access
smbclient //server/shared -U smbuser

DNS Configuration (BIND)¶

apt install bind9

# Key files
/etc/bind/named.conf              # main config
/etc/bind/named.conf.local        # local zones
/etc/bind/named.conf.options      # options, forwarders

Basic Caching DNS¶

# /etc/bind/named.conf.options
options {
    directory "/var/cache/bind";
    forwarders {
        8.8.8.8;
        8.8.4.4;
    };
    listen-on { any; };
    allow-query { any; };
};

Database (MariaDB/MySQL)¶

apt install mariadb-server
mysql_secure_installation
mysql -u root -p

CREATE DATABASE mydb;
CREATE USER 'myuser'@'localhost' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON mydb.* TO 'myuser'@'localhost';
FLUSH PRIVILEGES;

Key Takeaways for the Exam¶

LVM workflow: pvcreate -> vgcreate -> lvcreate -> mkfs -> mount -> fstab
After lvextend, resize filesystem: resize2fs (ext4) or xfs_growfs (XFS)
XFS can only grow, never shrink
Always use UUID in /etc/fstab (from blkid)
Use mount -a to test fstab entries before rebooting
Apache: a2ensite/a2dissite, apache2ctl configtest
Nginx: symlinks to sites-enabled, nginx -t
NFS: /etc/exports, exportfs -a
RAID: mdadm --create, check with cat /proc/mdstat
Swap file: create, chmod 600, mkswap, swapon, fstab