Disaster Recovery

Recovery procedure after disk failure requiring OS and VoIPmonitor reinstallation.

Overview

When a disk fails and requires replacement, recovery involves:

Customer: Replace hardware, install OS, configure network, provide remote access
Support: Install VoIPmonitor, restore configuration, verify operation

ℹ️ Note: Self-service installation is possible using Sniffer Installation and GUI Installation guides if you have VoIPmonitor expertise.

Step 1: Hardware & OS

Replace failed disks and install a supported OS:

OS	Status
Ubuntu 24.04 LTS	Recommended
Debian 12/13	Supported
Rocky Linux 9/10	Supported
CentOS 7	EOL - migrate to Rocky/Alma

⚠️ Warning: Do not copy binaries from old disk if OS version differs. Always install VoIPmonitor fresh using the official installer.

Step 2: Network Configuration

Configure network interfaces to match original server:

Same IP address (for fixed configurations)
DNS servers and routing
SPAN/TAP port connectivity (for sniffer servers)

Step 3: Timezone Configuration

⚠️ Warning: CRITICAL: PCAP paths use local time (/var/spool/voipmonitor/YYYY/MM/DD). Timezone mismatch prevents GUI from finding historical recordings.

# Check current timezone
timedatectl

# Set timezone (must match original server)
sudo timedatectl set-timezone Europe/Prague

# Verify
timedatectl

Step 4: Provide Remote Access

Choose one method for VoIPmonitor support staff:

Method A: Direct SSH

# Create support user (optional but recommended)
adduser supportuser
usermod -aG sudo supportuser

# Verify SSH is running
systemctl status sshd

Method B: VPN Access

Provide VPN credentials and server internal IP.

Method C: Reverse SSH Tunnel

For servers behind firewalls without direct SSH access:

# Run on your internal server (connects to your bastion host)
ssh -R 2222:localhost:22 -N support@bastion.yourdomain.com

# Support connects via: ssh -p 2222 user@bastion.yourdomain.com

Step 5: VoIPmonitor Installation

Support staff will install and configure based on deployment type:

Deployment Type	Tasks
Sniffer-Only	Install binary, configure interface, connect to central server, restore `voipmonitor.conf`
GUI/Database	Install MariaDB/MySQL, GUI, PHP dependencies, restore configuration
All-in-One	All of the above, reconstruct database from PCAPs if needed

Step 6: Data Recovery

Case 1: Database Backup Available

# Restore from mysqldump
gunzip < backup.sql.gz | mysql -u root -p voipmonitor

For GUI configuration restore, see Backup & Restore Guide.

Case 2: PCAP Files Survived

If PCAPs can be recovered from separate storage or mounted old disk:

# 1. Restore PCAP files to spooldir
rsync -avz /mnt/old_disk/var/spool/voipmonitor/ /var/spool/voipmonitor/

# 2. Create fresh database
mysql -e "CREATE DATABASE voipmonitor;"

# 3. Restore GUI configuration first (if available)
# See: Backing_Up_GUI_Configuration

# 4. Reconstruct database from PCAPs
voipmonitor --config-file=/etc/voipmonitor.conf --readpcapdir /var/spool/voipmonitor

ℹ️ Note: Processing PCAPs in restore mode can take significant time depending on data volume.

Case 3: No Backups

Historical data is permanently lost
System must be reconfigured from scratch
Implement backup strategy (see Prevention below)

Step 7: Verification

# Check service status
systemctl status voipmonitor

# View logs
journalctl -u voipmonitor -f

# For GUI server
systemctl status apache2  # or nginx

Verify in GUI:

Sensors connected (distributed mode)
New calls being captured
Historical recordings accessible (if restored)

Prevention

Implement these measures to minimize future data loss:

Measure	Description	Reference
GUI Backups	Daily automated backup of configuration, users, alerts	Backing_Up_GUI_Configuration
Separate PCAP Storage	Move `spooldir` to NAS/SAN/separate disk	Data Cleaning
Database Replication	Master-master or dual-write for HA	Redundant_database
Database Backups	Regular mysqldump to off-site storage	See below
Disk Health Monitoring	SMART monitoring for early warning	See below

Database Backup Cron

# /etc/cron.d/voipmonitor-backup
0 2 * * * root mysqldump -u root -pPASSWORD voipmonitor | gzip > /backup/db_$(date +\%Y\%m\%d).sql.gz

Disk Health Monitoring

# Install smartmontools
apt-get install smartmontools

# Check disk SMART status
smartctl -a /dev/sda

AI Summary for RAG

Summary: Disaster recovery procedure after VoIPmonitor server disk failure. Workflow: (1) Replace hardware; (2) Install supported OS (Ubuntu 24.04, Debian 12/13, Rocky Linux 9/10 recommended); (3) Configure network to match original; (4) Set timezone - CRITICAL because PCAP paths use local time format /var/spool/voipmonitor/YYYY/MM/DD; (5) Provide remote access to support (SSH, VPN, or reverse tunnel); (6) Support installs VoIPmonitor. Data recovery options: database backup restore via mysqldump, PCAP reconstruction using voipmonitor --readpcapdir /var/spool/voipmonitor, or start fresh if no backups. Prevention: automated GUI backups, separate PCAP storage on NAS/SAN, database replication, regular mysqldump, SMART disk monitoring.

Keywords: disaster recovery, disk failure, data recovery, OS reinstall, timezone configuration, PCAP restoration, database reconstruction, readpcapdir, spooldir, remote access, SSH tunnel, reverse tunnel, VPN, mysqldump, smartctl, backup strategy, NAS, SAN, high availability

Key Questions:

What do I do after a disk failure on my VoIPmonitor server?
How do I recover VoIPmonitor after complete disk failure?
Why is timezone critical after disk failure recovery?
How do I provide remote access to VoIPmonitor support?
How do I reconstruct VoIPmonitor database from PCAP files?
Can I recover PCAP files if the database is lost?
What backups should I have for disaster recovery?
How do I set up a reverse SSH tunnel for support access?