Implementing Backup Strategies

Overview

Design and implement backup strategies for databases, file systems, and cloud resources using tools like tar, rsync, pg_dump, mysqldump, AWS S3, and cloud-native snapshot APIs. Covers full, incremental, and differential backup schemes with retention policies, encryption, and automated verification.

Prerequisites

tar, rsync, or restic installed for file-level backups
Database client tools (pg_dump, mysqldump, mongodump) for database backups
AWS CLI configured with S3 write permissions (or equivalent GCP/Azure storage access)
Sufficient storage capacity at backup destination (local, NFS, or object storage)
Cron or systemd timer access for scheduling automated backups
GPG or OpenSSL for backup encryption at rest

Instructions

Inventory all data sources requiring backup: databases, application data directories, configuration files, secrets/certificates
Classify data by RPO (Recovery Point Objective) and RTO (Recovery Time Objective) requirements
Select backup strategy per data class: full daily + incremental hourly for databases, snapshot-based for block storage, rsync for file systems
Generate backup scripts using appropriate tools (pg_dump --format=custom, tar czf, rsync -avz --delete)
Configure retention policy: daily backups kept 7 days, weekly kept 4 weeks, monthly kept 12 months
Add encryption for backups containing sensitive data (gpg --encrypt or S3 server-side encryption with KMS)
Set up automated scheduling via cron jobs or systemd timers with proper logging
Implement backup verification: restore to a test environment on a weekly schedule and validate data integrity
Configure alerting for backup failures via email, Slack, or PagerDuty

Output

Backup shell scripts with logging, error handling, and lock files to prevent concurrent runs
Cron entries or systemd timer/service unit files
Retention policy configuration (lifecycle rules for S3, cleanup scripts for local)
Restore runbook with step-by-step recovery procedures
Monitoring configuration for backup success/failure alerts

Error Handling

Error	Cause	Solution
`No space left on device`	Backup destination full	Verify retention cleanup is running; increase storage or reduce retention window
`pg_dump: connection refused`	Database not accepting connections or wrong credentials	Check `pg_hba.conf`, verify connection string, and test with `psql` first
`rsync: connection unexpectedly closed`	Network interruption or SSH timeout	Add `--timeout=300` and `--partial` flags; use persistent SSH tunnel
`S3 upload failed: Access Denied`	IAM policy missing `s3:PutObject` permission	Attach proper IAM policy; verify bucket policy allows writes from the backup source
`Backup file corrupted on restore`	Incomplete write or disk error during backup	Add checksum verification (`sha256sum`) after backup; test restores regularly

Examples

"Create a backup strategy for a PostgreSQL database: full dump nightly to S3, WAL archiving for point-in-time recovery, 30-day retention."
"Generate rsync scripts to mirror /var/www to a remote NAS with incremental daily backups and weekly full backups."
"Implement encrypted backups for a MongoDB replica set with automated restore testing every Sunday."

Resources

PostgreSQL backup guide: https://www.postgresql.org/docs/current/backup.html
AWS S3 lifecycle policies: https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-lifecycle-mgmt.html
Restic backup tool: https://restic.readthedocs.io/
Backup best practices (3-2-1 rule): https://www.veeam.com/blog/321-backup-rule.html

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