*This post is a continuation of our Gen 2 SDP General Availability announcement. If you haven't read that yet, start there for a full overview of what Gen 2 SDP brings to the table.*
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Background
Gen 2 SDP introduces a new model for block storage where capacity, IOPS, and throughput are independently configurable. For customers running workloads on Gen 1 profiles, the key question has been: how do I upgrade without disruption?
Today, that answer is simple — in-place, zero-downtime migration from Gen 1 to Gen 2 SDP is now available.
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How to right-size sdp profiles to match Gen1 profiles?
Here is the simple table for your conveniece to map current Gen1 profiles to Gen2 profile’s IOPS & Throughput levers.
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Profile
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IOPS
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Throughput (MBps)
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3 IOPS/GB
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GB x 3
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IOPS x 0.016
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5 IOPS/GB
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GB x 5
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IOPS x 0.016
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10 IOPS/GB
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GB x 10
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IOPS x 0.25
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Custom IOPS
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Preset IOPS
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IOPS x 0.25
|
Note:
- To convert MBps (MB/s) to Mbps (Mb/s), just multiply throughput by factor of 8
- Minimum: 3,000 IOPS, 125 MB/s
- Maximum: 64,000 IOPS, 1,024 MB/s
Example:
A 1000 GB volume at 5 IOPS tier = 5,000 IOPS
Throughput = 5,000 (IOPS) × 0.016 = 80 MB/s → Rounded to 125 MB/s minimum baseline
SDP equivalent is 1000 GB, 5,000 IOPS and 125 MB/s throughput
Key takeaway: For many smaller or moderate workloads, the included baseline (3,000 IOPS / 125 MB/s) already meets or exceeds existing Gen 1 performance.
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Understanding the Cost Model: Why Gen 2 SDP Is More Efficient
Gen 2 SDP uses a decoupled pricing model across capacity, IOPS, and throughput. This allows independent tuning without requiring changes to volume size.
Refer to pricing documentation for details.
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Key Capabilities and Benefits of migration functionality
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In-Place Volume Migration
No detach, no recreation — migration happens in place with continuous I/O.
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Seamless Billing Transition
Automatic switch to Gen 2 pricing with no overlap or manual action.
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Universal Volume Support
Boot and data volumes, with or without snapshots, are supported.
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Independent Performance Tuning
Configure capacity, IOPS, and throughput independently.
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Future-Proof Platform
Up to 64,000 IOPS and 1,024 MB/s, with access to future enhancements.
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What Does Not Change After Migration
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Volume ID and attachment remain unchanged
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No application or mount-point changes required
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No data copy or restore process involved
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Existing snapshots remain intact and fully usable post-migration
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How to Migrate
Migrating a volume is straightforward and can be initiated through the IBM Cloud Console, CLI, or API.
Via the Console:
Navigate to your Block Storage volume list → select the volume → choose Migrate Volume → confirm the target Gen 2 SDP profile, you may optionally configure target IOPS and throughput as part of the migration step — or leave at defaults to inherit the Gen 2 SDP baseline. Once initiated, you can track status in real time via the Volume Jobs tab.
Via the CLI:
ibmcloud is volume-migrate VOLUME_ID --profile sdp
Via the API:
Use the Block Storage for VPC API to issue a POST /volumes/{id}/migrate request with the target profile set to sdp.
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How to Verify Your Migration Using the CLI
Once a migration is initiated, you can monitor its progress using the CLI:
ibmcloud is volume <VOLUME-ID>
Look for the volume status field. During migration, the volume will show a locked state. Once migration completes, the status transitions back to available and the profile will reflect sdp.
You can also list all active and recent volume jobs:
ibmcloud is volume-job <VOLUME-ID> --job <VOLUME-JOB-ID>
This gives you a timestamped view of job type, status, and completion — useful for auditing migrations across multiple volumes.
The same can be achieved through console - Just navigate to your Block Storage volume list → select the volume → go to volume jobs (new) tile. Customers can track progress of all volume jobs and check their completion status.
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Pricing During and After Migration
There is no charge for the migration process itself. Here is how billing works across the transition:
- While migration is in progress, the volume is billed at its existing Gen 1 profile rate
- Upon successful completion, billing automatically switches to the Gen 2 SDP model
- There is no billing overlap or pro-rated double-charge
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Limitations to Be Aware Of
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Migration rate: A maximum of 10 volume migrations are permitted per 24-hour period by default
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Immutable state during migration: The volume enters a locked state once migration begins — attach, detach, delete, and snapshot operations are not permitted until migration completes
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Snapshots are not modified during migration. However, existing snapshots remain fully usable and can be used to restore volumes in respective generation.
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Planning Your Migration at Scale
For customers managing a large number of volumes, we recommend the following approach:
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Inventory your Gen 1 volumes: Use the IBM Cloud Console or CLI to list all volumes and their current profiles. Identify which profile tiers (3, 5, 10 IOPS/GB, or Custom) each volume is on.
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Prioritize based on workload criticality and migration scheduling requirements
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Batch your migrations: Given the default limit of 10 migrations per 24-hour period, plan your migration waves accordingly — especially for large environments.
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Monitor via Volume Jobs: Use the Volume Jobs tab to track status across all in-flight migrations in a single view.
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Validate post-migration: After each migration completes, verify the volume profile, IOPS, and throughput settings reflect the Gen 2 SDP configuration you expect before proceeding to the next batch.
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Final Thought
Gen 2 SDP is the foundation for future block storage capabilities on IBM Cloud. With in-place migration available, existing Gen 1 volumes can now be upgraded seamlessly.
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Get Started
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*The migration capability is now generally available across all IBM Cloud VPC regions. Gen 2 SDP profile pricing details can be found on the IBM Cloud Block Storage pricing page.*
Authors:
Prathamesh Kadam | IaaS Product Management at IBM Cloud
Karthik Baskaran | IaaS Architect at IBM Cloud