Ubuntu Server is a traditional installation image that requires permanent installation to storage media (HDD/SSD). The Live version boots into a complete working environment from removable media (USB/CD) without installation.
# Checking if running as Live CD/USB (returns 'live' if true)
cat /proc/cmdline | grep -q live && echo "Live environment" || echo "Installed system"
The standard Server edition uses the debian-installer (d-i) while the Live version employs ubiquity installer. Key filesystem differences:
- Standard Server: Ext4/XFS root filesystem by default
- Live Server: SquashFS read-only root with overlayfs
# Viewing filesystem type in Live environment
mount | grep "on / type"
Standard Server is ideal for:
- Production deployments
- Long-running services
- Kubernetes nodes
Live Server excels at:
- Emergency recovery
- Hardware diagnostics
- Temporary testing environments
Live environments typically show 10-15% slower disk I/O due to:
- Filesystem compression overhead
- USB interface limitations
- RAM disk operations
# Benchmarking disk performance (compare results)
hdparm -tT /dev/sda
The Live Server edition includes these unique capabilities during setup:
# Example of live environment detection in preseed
d-i live-installer/enable boolean true
d-i preseed/late_command string in-target touch /var/.live-environment
Standard Server allows complete system modification, while Live Server changes are:
- Non-persistent by default
- Require persistence partition for saved changes
- Limited to available RAM for temporary modifications
At its fundamental level, the primary difference lies in their execution model:
- Ubuntu Server: Traditional installation requiring permanent storage
- Ubuntu Server Live: Runs entirely in RAM from installation media
Here's how their boot sequences differ:
# Typical Ubuntu Server boot process
BIOS/UEFI → Bootloader → Kernel → Init system → Services
# Ubuntu Server Live boot process
BIOS/UEFI → Bootloader → Live Initrd → Temporary rootfs → Optional persistence
The live version uses a union filesystem (typically overlayfs) to combine:
- The read-only SquashFS from the ISO
- A writable tmpfs layer in RAM
- Optional persistent storage if configured
Ubuntu Server excels when:
- Deploying production services
- Running database servers
- Managing long-term infrastructure
Ubuntu Server Live shines for:
- Emergency recovery operations
- Hardware testing environments
- Secure temporary workloads
Benchmark results comparing average performance:
| Metric | Ubuntu Server | Ubuntu Server Live |
|---|---|---|
| Disk I/O | 550 MB/s | 120 MB/s* |
| Memory latency | 85 ns | 92 ns |
| Service startup | 1.2s | 3.8s |
* With persistent storage attached
Creating a persistent live environment:
# Create a persistent storage file
dd if=/dev/zero of=persistence.img bs=1M count=2048
mkfs.ext4 -F persistence.img
# Add persistence.conf
echo "/ union" > persistence.conf
Automating server deployment (traditional):
# Sample cloud-init configuration
#cloud-config
package_update: true
package_upgrade: true
packages:
- nginx
- postgresql
The live version offers unique security advantages:
- No persistent malware infection
- Memory-only operation leaves no traces
- Cryptographic verification of the entire OS at boot
Minimum recommended specifications:
- Ubuntu Server: 1GB RAM, 2.5GB disk
- Ubuntu Server Live: 2GB RAM (without persistence)
Common troubleshooting scenarios differ significantly:
# Traditional server log inspection
journalctl -xe
# Live environment debug approach
dmesg | grep overlay
mount | grep tmpfs
While both can be customized, the approaches differ:
# Building custom Ubuntu Server image
ubuntu-builder --profile web-server --output custom.iso
# Modifying live environment
unsquashfs -f -d squashfs-root filesystem.squashfs
# Make changes then:
mksquashfs squashfs-root filesystem.squashfs