Explanation
Why the waste happens and who it affects.
They remain fully supported, but Oracle states that the latest shapes offer newer hardware and a better price-performance ratio, and for each previous-generation series it names current replacements such as VM.Standard.E4.Flex, E5.Flex, E6.Flex or the Ampere A1, A2 and A4 Flex shapes.
The clearest unit-price gap is on the fixed VM.Standard2 series. These shapes bundle 15 GB of memory with every OCPU, and Oracle's price list charges the X7 standard SKU at $0.0638 per OCPU-hour, while VM.Standard.E4.Flex is $0.025 per OCPU-hour plus $0.0015 per GB-hour of memory chosen independently. Moving a Standard2 VM to a current flexible shape, and sizing memory to what the workload uses, lowers the hourly rate before any rightsizing. For other series the unit price gap is smaller or reversed (VM.Standard.E2 is $0.03 per OCPU-hour with fixed memory), so the case rests on performance per OCPU and on being able to size OCPU and memory separately. Capacity is also a factor: Oracle notes that previous-generation capacity may be limited in high-demand regions.
Billing model
The pricing dimensions that drive this cost.
All figures are USD unit prices from Oracle's public price list and exclude negotiated discounts.
- Fixed previous-generation shapes
- Billed per OCPU-hour at the shape's SKU rate with memory fixed by the shape (for example 15 GB per OCPU on VM.Standard2)
- Flexible current shapes
- Billed per OCPU-hour plus per GB-hour of memory, with OCPU count and memory set independently
- Per-second billing
- Current compute resources are billed per second with a one-minute minimum
- Shape change
- Billed to the nearest second for each shape used, so the new rate applies from the change
How to detect
4 checks to find it in your estate.
- List instances whose shape belongs to a series in Oracle's Previous Generation VM Shapes list (VM.Standard1, VM.Standard.B1, VM.Standard2, VM.Standard.E2, VM.Standard.E3, VM.DenseIO1, VM.DenseIO2), for example with oci compute instance list and the shape field, across all compartments
- For each, compare CPU and memory use (CpuUtilization and MemoryUtilization in oci_computeagent) with the fixed shape's allocation to see how much of the bundled memory or OCPU is unused
- Price the current configuration against a current flexible shape sized to measured OCPU and memory, using Oracle's price list or Cost Estimator, and prioritize VM.Standard2 instances with low memory use
- Check image compatibility with the target shape in the console (image details, compatible shapes) or with ListShapes for the image OCID
How to fix
5 ways to remove the waste.
- For VM shapes that support it, use Change shape to move to a current flexible shape such as VM.Standard.E4.Flex, E5.Flex or E6.Flex, choosing OCPU and memory from measured usage; a fixed shape can be changed to a flexible shape
- Consider Arm-based Ampere Flex shapes (A1, A2, A4) for workloads with Arm-compatible software, after testing
- For bare metal instances and VMs that cannot change shape, terminate the instance while keeping the boot volume, then create a new instance on a current shape from that boot volume
- Plan for the reboot: a running instance is rebooted during a shape change, network interface names can change on some guest OSs, and Windows Server 2019 on VM.Standard2 can only change shape within the same series
- Confirm service limits for the target shape first; without them the instance keeps its original shape
Documentation
Vendor references for pricing and configuration.