When upgrading software systems, understanding the difference between in-place and out-of-place upgrades is crucial. Each method has unique benefits and drawbacks depending on the context, system requirements, and risk tolerance.

• In-Place Upgrade: This upgrade method installs the new version directly over the existing system on the same hardware and file structure.

• Out-of-Place Upgrade: This method installs the new version on separate hardware or a different environment, allowing for parallel setup.

Aspect	In-Place Upgrade	Out-of-Place Upgrade
Definition	Replaces the current version on the same system	Installs new version in a separate environment
System Downtime	Higher downtime required	Lower downtime, can be prepared in advance
Rollback	Difficult and risky	Easier, revert to the old environment
Risk Level	Higher (affects current system directly)	Lower (no change to current system until ready)
Resource Requirement	Lower (no extra system needed)	Higher (needs separate environment/hardware)
Data Migration	Not usually required	Required (move data to the new system)
Speed of Upgrade	Faster to execute	Slower due to setup and data migration
Common Use Cases	Minor updates, patches	Major upgrades, mission-critical systems

• Useful for minor software or OS patches.

• Environments where resource constraints exist.

• Situations where rollback is unlikely to be needed.

• Recommended for mission-critical applications.

• Major upgrades (e.g., database engine upgrades).

• Environments requiring high availability and rollback capability.

In-Place: Upgrading Windows 10 to Windows 11 on the same PC.

Out-of-Place: Installing Windows 11 on a new partition or different PC.

In-Place: Upgrading Oracle 12c to 19c on the same instance.

Out-of-Place: Installing Oracle 19c on a new server and migrating data.

In-Place: Updating a compute instance’s OS or database version directly on the existing virtual machine.

Out-of-Place: Creating a new compute instance or database in OCI with the upgraded version and migrating apps/data.

In-Place: Performing an OS or software upgrade on an existing Azure VM.

Out-of-Place: Deploying a new VM or Azure service with updated configurations, then migrating services and users.

In-Place: Upgrading a running EC2 instance’s OS or RDS database version directly.

Out-of-Place: Launching a new EC2 or RDS instance with updated settings, and then migrating workloads.

In-Place: Performing updates on a running GCE VM or managed database service like Cloud SQL.

Out-of-Place: Creating a new GCE instance or Cloud SQL environment with the latest version and switching traffic after migration.

Choosing between in-place and out-of-place upgrades depends on your system's criticality, your rollback requirements, and available resources. Understanding both approaches ensures smoother upgrades with minimal disruption and maximum safety.