Migrations

Purpose

This page covers notes, labs, personal setup items, deviations, etc. covered in the Design migrations Learn module.

Evaluate with CAF

There’s an entire unit on Cloud Adoption Framework so there is not a lot of detail here. Essentially, there are seven best practice steps: Strategy, Plan, Ready, Adopt, Govern, Manage and Organize (the main word will vary across documents but the ideas of each phase are consistent).

Migration Strategies

There are also five migration patterns that will vary depending on the companies landscape:

  1. Rehost - Lift and shift
  2. Refactor - Minimal changes to resources but taking advantage of easy PaaS solutions where possible. e.g. Instead of a VM with SQL Server use a Azure SQL Database.
  3. Rearchitect - Change your solution around to break down items and significantly buy into the PaaS/SaaS options.
  4. Rebuild - Completely break things down and lean heavily into the platform services. A benefit is this allows for some greenfield deployments where you don’t carry your technical debt forward.
  5. Replace - Somewhat part of the rebuild option. Basically rehost and then remove a key component because it is no longer necessary in the cloud. File server could be replaced with an Azure File Share.

Migration Tools

A full list of migration tools can be found here with the heavy hitters listed below.

  1. Azure TCO Calculator - Estimates how much you save (or lose) by migrating to Azure
  2. Service Map - Identify dependencies between resources that need to migrate.
    • Requires an agent to be installed on source VMs
  3. Azure Migrate - Move VMs, Databases, Web Apps, etc. (absolutely amazing tool)
    1. Provides single, unified portal/platform for the migration process
    2. Test includes the six core tools of the migration platform
      1. Azure Migrate: Server Assessment
      2. Azure Migrate: Server migration
      3. SQL Server Data Migration Assistant (DMA)
      4. Azure Database Migration Service
      5. Web app migration assistant
        1. Install local agent to assess ASP.NET web apps (not database movement - use DMA)
      6. Azure Data Box
  4. Data Migration Assistant and Database Migration Service
    1. Move SQL and no-SQL data
  5. Advisor - Get insights to improve reliability, cost and security

TCO and Service map will give a good idea of what strategy you’re looking at. e.g. if costs are too high rebuilding or rearchitect may be necessary.

Azure Resource Mover

Not exactly part of the migration workflow but it kind of fits in. If resources end up in the wrong subscription, resource group, region, etc. then the Resource Mover and migrate a number of items. Note that there are some items that will not move (certificates).

Azure Database Migration Service

There are two options on how to move the data:

  1. Online migration: leave everything running and data syncs between systems in real time.
  2. Offline migration: requires shutting down systems, moving and then powering up.

The SQL Server Data Migration Assistant (DMA) guides users through the data migration process.

  1. Assess databases: target databases for migration
    1. Generates a report with recommendations and alternate approaches
    2. Review the report and address any issues, rinse and repeat until report is OK
  2. Migrate scheme: separate the schema from the data and move it to the target SQL Database instances
  3. migrate data and verify: copy the data to the target instance and verify the integrity

Azure Storage Migration Service

Used for migrating unstructured data (blobs) from various on-prem systems to Azure.

  • Located in the Windows Admin Center

  • Conducts an inventory of data, transfers files, file shares and security configuration from the sources

  • Multiple migrations can be performed at once in the Admin center

  • During migration

    • When you use the cut over option, the destination servers assume the former identities of the source servers.
    • This option enables users and apps to access your existing data without making any changes.
      • This creates a conflict that needs to be resolved

  • After migration

    • When migration is complete, your source servers enter a maintenance state.
    • The servers still contain their original files, but the data isn’t available to users and apps.

  • Decommission

    • Don’t remove files from your source servers until you’re ready to completely decommission the servers.
    • The decommission process can be completed at your convenience.

Azure File Sync

AZ-104 stuff on how it works so no details here. However, it’s worth mentioning that Azure File Sync can be used as a migration target for file shares or other blob data.

Physical Data Migration

Azure Import/Export is another AZ-104 item, the import/export service allows for the physical transfer of mass amounts of data into/out of Azure.

  • Only works to/from Blob storage
    • Cannot use Azure Files or File Share
  • A set of disks is prepped, loaded with data and then shipped

Azure Data Box: Azure ships a box device that is then added to the local network. It is then setup, data loaded (up to 80TB) and then sent back to Azure.

Compare Azure Import/Export Azure Data Box
Form factor Internal SATA HDDs or SDDs Secure, tamper-proof, single hardware appliance
Microsoft manages shipping logistics No Yes
Integrates with partner products No Yes
Custom appliance No Yes

Actual Migration

  1. Deploy the cloud infrastructure targets. e.g. VNETs, Storage accounts, NVAs, etc.
    • Azure Migrate, Azure Database Migrate, etc. are tools to assist with migration.
  2. Migrate the workloads. Pilot the migration and start moving things over.
  3. Decommission old systems. Don’t get rid of everything (e.g. keep backups) but start gracefully turning things down.

Optimize Workloads

After migration is complete start optimizing for cost and performance. The strategy used (rehost, rebuild, etc.) plays heavily into how much work there is to do here, but there is always room for improvement around cost optimizations or solving for unforeseen pain points.

  • Use the Advisor recommendations and cost analysis tools for low hanging fruit.

Monitor Workloads

Various landing zone setups will already have monitoring rules setup. However, they may need adjustments to metrics monitored, new rules, less rules, etc. to get to a good spot.