Disaster Recovery Design
Overview
Comprehensive disaster recovery architecture and procedures for enterprise infrastructure resilience and business continuity.
DR Architecture Components
Multi-Site Design
graph TB
subgraph "Primary Site"
PrimaryDC[Primary Data Center]
PrimaryServers[Production Servers]
PrimaryStorage[Primary Storage]
PrimaryNetwork[Primary Network Infrastructure]
PrimaryUsers[Primary User Base]
end
subgraph "Secondary Site"
SecondaryDC[Secondary Data Center]
SecondaryServers[Standby Servers]
SecondaryStorage[Replicated Storage]
SecondaryNetwork[Secondary Network Infrastructure]
SecondaryUsers[Backup User Access]
end
subgraph "Cloud DR Site"
CloudDC[Cloud Data Center]
CloudVMs[Cloud Virtual Machines]
CloudStorage[Cloud Storage]
CloudNetwork[Cloud Network]
CloudUsers[Cloud User Access]
end
subgraph "Replication Services"
DataReplication[Data Replication]
AppReplication[Application Replication]
ConfigReplication[Configuration Replication]
end
PrimaryDC <--> DataReplication
DataReplication <--> SecondaryDC
DataReplication <--> CloudDC
PrimaryServers --> AppReplication
AppReplication --> SecondaryServers
AppReplication --> CloudVMs
PrimaryStorage --> ConfigReplication
ConfigReplication --> SecondaryStorage
ConfigReplication --> CloudStorage
Recovery Tiers
graph LR
subgraph "Tier 1 - Critical"
T1Apps[Mission Critical Apps]
T1Data[Critical Databases]
T1Services[Core Services]
T1Recovery[RTO: 1 Hour, RPO: 15 Min]
end
subgraph "Tier 2 - Important"
T2Apps[Important Applications]
T2Data[Business Databases]
T2Services[Supporting Services]
T2Recovery[RTO: 4 Hours, RPO: 1 Hour]
end
subgraph "Tier 3 - Standard"
T3Apps[Standard Applications]
T3Data[Operational Data]
T3Services[General Services]
T3Recovery[RTO: 24 Hours, RPO: 4 Hours]
end
subgraph "Tier 4 - Low Priority"
T4Apps[Non-Critical Apps]
T4Data[Archival Data]
T4Services[Optional Services]
T4Recovery[RTO: 72 Hours, RPO: 24 Hours]
end
Data Protection Strategy
Backup Architecture
graph TB
subgraph "Data Sources"
Databases[Database Systems]
FileServers[File Servers]
VirtualMachines[Virtual Machines]
Applications[Application Data]
Configurations[System Configurations]
end
subgraph "Backup Infrastructure"
BackupServers[Backup Servers]
BackupStorage[Backup Storage]
DedupAppliances[Deduplication Appliances]
TapeLibrary[Tape Library]
end
subgraph "Backup Targets"
LocalStorage[Local Backup Storage]
OffSiteStorage[Off-Site Storage]
CloudBackup[Cloud Backup]
TapeArchive[Tape Archive]
end
subgraph "Backup Processes"
FullBackup[Full Backup]
IncrementalBackup[Incremental Backup]
DifferentialBackup[Differential Backup]
ContinuousBackup[Continuous Backup]
end
Databases --> BackupServers
FileServers --> BackupServers
VirtualMachines --> BackupServers
Applications --> BackupServers
BackupServers --> BackupStorage
BackupStorage --> DedupAppliances
DedupAppliances --> LocalStorage
LocalStorage --> OffSiteStorage
LocalStorage --> CloudBackup
OffSiteStorage --> TapeArchive
Replication Technologies
Database Replication
sequenceDiagram
participant Primary as Primary Database
participant Replica as Secondary Replica
participant DR as DR Site Database
participant Monitor as Replication Monitor
Primary->>Replica: Synchronous Replication
Primary->>DR: Asynchronous Replication
Primary->>Monitor: Replication Status
Replica->>Monitor: Health Check
DR->>Monitor: Replication Lag
Monitor->>Primary: Performance Metrics
Note over Primary,DR: Continuous Data Protection
Note over Monitor: Real-time Monitoring
Storage Replication
- Block-level replication
- File-level replication
- Application-consistent snapshots
- Cross-site storage mirroring
Recovery Procedures
Failover Process
graph TB
subgraph "Disaster Detection"
MonitoringSystem[Monitoring System]
AlertSystem[Alert System]
AutoDetection[Automatic Detection]
ManualTrigger[Manual Trigger]
end
subgraph "Decision Process"
IncidentAssessment[Incident Assessment]
DRTeamActivation[DR Team Activation]
FailoverDecision[Failover Decision]
StakeholderNotification[Stakeholder Notification]
end
subgraph "Failover Execution"
DNSUpdate[DNS Updates]
NetworkRerouting[Network Rerouting]
ServiceActivation[Service Activation]
DataValidation[Data Validation]
UserNotification[User Notification]
end
subgraph "Post-Failover"
SystemMonitoring[System Monitoring]
PerformanceTuning[Performance Tuning]
UserSupport[User Support]
IncidentDocumentation[Incident Documentation]
end
MonitoringSystem --> IncidentAssessment
AlertSystem --> IncidentAssessment
AutoDetection --> DRTeamActivation
ManualTrigger --> DRTeamActivation
IncidentAssessment --> FailoverDecision
FailoverDecision --> DNSUpdate
DNSUpdate --> NetworkRerouting
NetworkRerouting --> ServiceActivation
ServiceActivation --> DataValidation
DataValidation --> UserNotification
UserNotification --> SystemMonitoring
Recovery Testing
Testing Schedule
Test Type | Frequency | Scope | Duration |
---|---|---|---|
Backup Restore Test | Monthly | Individual systems | 2-4 hours |
Application Failover | Quarterly | Critical applications | 4-8 hours |
Site Failover Test | Bi-annually | Full DR site | 8-24 hours |
Disaster Simulation | Annually | Complete infrastructure | 24-72 hours |
Test Procedures
Planning Phase
- Test scope definition
- Resource allocation
- Timeline establishment
- Risk assessment
Execution Phase
- Controlled failover
- System validation
- Performance testing
- User acceptance testing
Validation Phase
- Data integrity checks
- Functionality verification
- Performance validation
- Security assessment
Documentation Phase
- Test results documentation
- Issues identification
- Improvement recommendations
- Procedure updates
Business Continuity Planning
Recovery Objectives
Recovery Time Objective (RTO)
graph LR
subgraph "RTO Definitions"
Critical[Critical Systems: 1 Hour]
Important[Important Systems: 4 Hours]
Standard[Standard Systems: 24 Hours]
NonCritical[Non-Critical: 72 Hours]
end
subgraph "Impact Analysis"
Financial[Financial Impact]
Operational[Operational Impact]
Reputation[Reputation Impact]
Compliance[Compliance Impact]
end
Critical --> Financial
Important --> Operational
Standard --> Reputation
NonCritical --> Compliance
Recovery Point Objective (RPO)
- Mission Critical: 15 minutes data loss maximum
- Business Critical: 1 hour data loss maximum
- Important: 4 hours data loss maximum
- Standard: 24 hours data loss maximum
Communication Plan
Internal Communication
graph TB
subgraph "DR Team"
DRManager[DR Manager]
TechnicalLead[Technical Lead]
NetworkAdmin[Network Admin]
SystemAdmin[System Admin]
DatabaseAdmin[Database Admin]
end
subgraph "Management"
CTO[Chief Technology Officer]
CEO[Chief Executive Officer]
Operations[Operations Manager]
Communications[Communications Director]
end
subgraph "External Stakeholders"
Customers[Customers]
Vendors[Vendors]
Partners[Partners]
Regulators[Regulators]
end
DRManager --> CTO
TechnicalLead --> Operations
CTO --> CEO
CEO --> Communications
Communications --> Customers
Communications --> Vendors
Operations --> Partners
Operations --> Regulators
Communication Channels
- Primary: Corporate email and phone systems
- Secondary: Mobile phones and personal email
- Emergency: Satellite phones and radio communication
- Public: Website updates and social media
Technology Implementation
Automation Tools
# DR Automation Framework
class DisasterRecoveryOrchestrator {
[string]$PrimarySite
[string]$DRSite
[hashtable]$Services
[string]$ReplicationStatus
DisasterRecoveryOrchestrator([string]$Primary, [string]$DR) {
$this.PrimarySite = $Primary
$this.DRSite = $DR
$this.Services = @{}
$this.ReplicationStatus = "Active"
}
[void]InitiateFailover([string]$ServiceTier) {
Write-Host "Initiating failover for $ServiceTier services" -ForegroundColor Yellow
# Stop services at primary site
$this.StopPrimaryServices($ServiceTier)
# Start services at DR site
$this.StartDRServices($ServiceTier)
# Update DNS and routing
$this.UpdateNetworkRouting()
# Validate services
$this.ValidateServices($ServiceTier)
}
[void]StopPrimaryServices([string]$Tier) {
$TierServices = $this.Services[$Tier]
foreach ($Service in $TierServices) {
try {
Stop-Service $Service -Force
Write-Host "Stopped service: $Service" -ForegroundColor Green
}
catch {
Write-Error "Failed to stop service $Service : $($_.Exception.Message)"
}
}
}
[void]StartDRServices([string]$Tier) {
$TierServices = $this.Services[$Tier]
foreach ($Service in $TierServices) {
try {
Invoke-Command -ComputerName $this.DRSite -ScriptBlock {
Start-Service $using:Service
}
Write-Host "Started DR service: $Service" -ForegroundColor Green
}
catch {
Write-Error "Failed to start DR service $Service : $($_.Exception.Message)"
}
}
}
[void]UpdateNetworkRouting() {
# Update DNS records
# Modify load balancer configuration
# Update firewall rules
Write-Host "Network routing updated to DR site" -ForegroundColor Green
}
[bool]ValidateServices([string]$Tier) {
$ValidationResults = @()
$TierServices = $this.Services[$Tier]
foreach ($Service in $TierServices) {
$ServiceCheck = $this.TestServiceHealth($Service)
$ValidationResults += $ServiceCheck
}
return ($ValidationResults | Where-Object {$_ -eq $false}).Count -eq 0
}
[bool]TestServiceHealth([string]$Service) {
# Implement service-specific health checks
return $true
}
}
# DR Testing Framework
function Start-DRTest {
[CmdletBinding()]
param(
[Parameter(Mandatory)]
[ValidateSet("Backup", "Application", "Site", "Full")]
[string]$TestType,
[Parameter(Mandatory)]
[string]$TestScope,
[Parameter()]
[string]$NotificationList = "dr-team@company.com"
)
$TestStart = Get-Date
Write-Host "Starting DR Test: $TestType" -ForegroundColor Cyan
try {
switch ($TestType) {
"Backup" {
$Result = Test-BackupRestore -Scope $TestScope
}
"Application" {
$Result = Test-ApplicationFailover -Scope $TestScope
}
"Site" {
$Result = Test-SiteFailover -Scope $TestScope
}
"Full" {
$Result = Test-FullDR -Scope $TestScope
}
}
$TestEnd = Get-Date
$Duration = $TestEnd - $TestStart
$TestReport = @{
TestType = $TestType
Scope = $TestScope
StartTime = $TestStart
EndTime = $TestEnd
Duration = $Duration
Result = $Result
Issues = $Result.Issues
Recommendations = $Result.Recommendations
}
Send-DRTestReport -Report $TestReport -Recipients $NotificationList
}
catch {
Write-Error "DR Test failed: $($_.Exception.Message)"
}
}
Monitoring and Alerting
- Replication lag monitoring
- Backup job status tracking
- DR site health checks
- Network connectivity monitoring
- Performance baseline comparison
Cost Optimization
DR Cost Management
Tiered Recovery Strategy
- Match recovery requirements to business criticality
- Use appropriate technology for each tier
- Regular cost-benefit analysis
Cloud DR Solutions
- Pay-as-you-go model
- Reserved capacity for critical systems
- Automated scaling during disasters
Resource Optimization
- Right-sizing DR infrastructure
- Shared DR sites for multiple applications
- Regular capacity planning reviews
Compliance and Governance
Regulatory Requirements
- Data residency requirements
- Recovery time mandates
- Audit trail maintenance
- Compliance reporting
Documentation Standards
- DR procedures documentation
- Test result records
- Incident response logs
- Change management records