Backup, DR & updates

Backup vs Site Recovery, update management.

Keeping services available and recoverable is a defining administrator responsibility. Backup, disaster recovery, and update management protect against data loss, site failure, and vulnerabilities respectively.

Backup and disaster recovery

Two distinct capabilities protect different failure modes. Azure Backup recovers lost or corrupted data: you define backup policies (frequency, retention) on VMs, files, and databases, storing recovery points in a Recovery Services vault, and restore individual items or whole resources when needed. Azure Site Recovery (ASR) keeps the workload running through a site failure: it replicates VMs to another region and orchestrates failover, so a regional outage becomes a controlled failover rather than an outage. The distinction matters — Backup answers "we lost data, restore it", ASR answers "the region is down, run elsewhere". Critical production workloads need both: a backup policy for data protection and, where the business requires surviving a regional event, a replication and failover plan with tested runbooks.

#  CAPABILITY          PROTECTS AGAINST        MECHANISM
#  Azure Backup     →  data loss/corruption     recovery points in a vault
#  Site Recovery    →  regional/site outage     replicate + orchestrated failover
#
# Backup an Azure VM with a policy:
az backup protection enable-for-vm -g app-rg \
  --vault-name contoso-vault --vm web-01 --policy-name DailyPolicy
# Test restore and test failover regularly — untested recovery is not recovery.

Update and configuration management

Keeping systems patched and consistent is ongoing management work. Azure Update Manager assesses and deploys OS updates across Azure and hybrid VMs on a schedule, so patching is systematic rather than ad hoc — important because unpatched systems are a top vulnerability. For configuration, tools like Azure Automation (runbooks), Desired State Configuration, and increasingly Azure Machine Configuration keep systems in a defined state and remediate drift. And Azure Advisor continuously surfaces recommendations across reliability, security, performance, and cost, giving the administrator a prioritized list of improvements. Together, backup and DR (recoverability), update management (patched systems), and configuration management (consistent state) are what keep an Azure estate reliable and secure over time — the operational disciplines behind a well-run platform, not one-time setup.