Data Management Glossary
FabricPool
What Is NetApp FabricPool?
FabricPool is a NetApp ONTAP storage technology that automatically tiers inactive data blocks from an all-flash performance tier to lower-cost object storage, either on premises or in the public cloud. ONTAP presents the flash tier and the object tier as a single logical pool and decides which blocks live where.
FabricPool is a form of storage-based tiering, also called block-level tiering. The storage array moves pieces of files, not whole files, and it keeps control over how that data is read back. That design choice determines how much a FabricPool deployment saves, what happens when you refresh storage, and whether the tiered data is usable for anything outside the array.
Read more about storage pools.
Enterprise data storage vendors have had a complicated relationship with data tiering. While some storage vendors continue to make claims about needing no tiers, most data storage vendors now acknowledge that 70%+ of unstructured file data is cold data and provide options for tiering to lower-cost storage. While lower cost drives were initially the target for the cold tier, many vendors now also offer tiering through their file system to object storage on-premises or in the cloud.
Storage-based data tiering and pools-based techniques to move data within a single architecture or operating system can deliver cost savings for system data such as snapshots. However, storage tiering introduces many limitations when it comes to flexible data policies, storage cost savings, ransomware defense, broader data access and unstructured data management needs.
Read the blog post: What you need to know before jumping into the cloud tiering pool
Download the white paper: Cloud Tiering: Storage-Based vs Gateways vs File-Based: Which is Better and Why?
Learn more about the Komprise path to the cloud for file and object data.
How FabricPool Tiering Works
FabricPool attaches an object store, called the cloud tier, to an all-flash aggregate, called the local tier. A tiering policy set on each volume controls what moves:
- Snapshot-only: tiers blocks referenced only by Snapshot copies once they go cold.
- Auto: tiers any cold block, including blocks in the active file system, after a cooling period of inactivity.
- All: sends data directly to the cloud tier, typically for secondary or data protection volumes.
- None: keeps all data on the flash tier.
ONTAP groups cold blocks into larger objects and writes them to the bucket in its own format. The files are not reassembled in the object store. Only ONTAP can read the tiered data, so applications, cloud services, and other storage systems see a bucket of ONTAP objects, not a set of usable files.
Why Tiering Matters for Unstructured Data
Tiering exists because most file data stops being used soon after it is created. More than 70% of unstructured file data is cold, yet it sits on the same flash as active data. Unstructured data also grows 20% to 150% per year depending on the industry, so the cold share of a flash system keeps getting larger.
Files are harder to tier well than structured records. There is no schema to tell you what a file is, naming is inconsistent, ownership changes, and a single share holds billions of files across departments, projects, and applications. A block-temperature metric tells the array which blocks are idle. It does not tell you whose data it is, what type it is, or whether it belongs in an archive, a retention bucket, or an AI pipeline.
Why Intelligent Tiering Matters More Now Than Ever
Flash is no longer getting cheaper. Gartner projects a 130% increase in combined DRAM and SSD prices by the end of 2026 compared with 2025. TrendForce expected enterprise SSD contract prices to rise 53% to 58% quarter over quarter in the first quarter of 2026, a record quarterly increase. Storage was already a large line item before the price surge. Data storage, backup, and disaster recovery consume more than 30% of the IT budget at 55% of enterprises.
Source: Komprise 2026 State of Unstructured Data Management Report
When flash costs more every quarter, every terabyte of cold data on flash costs more too. Buying more flash is the most expensive way to add capacity. The lower-cost move is to take cold data off flash and keep it accessible. The tiering method you choose decides how much of that saving you keep, and whether it survives your next storage refresh.
Intelligent tiering means tiering driven by analytics about the data itself: age, last access, file type, owner, project, and cost by location. It also means tiering that works across every storage vendor and keeps tiered files usable. Block-level tiering inside one array delivers only part of that.
What Is the Rehydration Penalty?
The rehydration penalty is the cost, time, and capacity consumed when tiered data has to be pulled back to primary storage before an operation completes. With block-level tiering, the tiered blocks mean nothing outside the array, so any operation that needs the whole dataset outside that array forces a recall.
Common data rehydration triggers include:
- Storage refresh or vendor change: moving to a new array or a different vendor requires reading every tiered block back through ONTAP before the data migrates.
- Cloud migration: the objects in the bucket are not files, so moving the data to a cloud file service or another platform requires a full recall first.
- Backup and scanning: backup jobs, antivirus scans, and other tools that read full files pull tiered blocks back, so the backup footprint does not shrink.
Each recall generates cloud egress and retrieval charges, consumes flash capacity you tiered to free up, and adds time to the project. The backup multiplier for primary data is typically 3X to 4X, so a tiering approach that leaves backups unchanged leaves most of the cost in place.
Read: Block-level Tiering vs File-level Tiering
The rehydration penalty is also what makes block-level tiering a form of lock-in. The more data you tier, the more it costs to leave.
Komprise Intelligent Data Management: File-Level Tiering Without Rehydration
File-level tiering moves whole files, not blocks, so the tiered data stays usable on its own. Komprise Intelligent Data Management tiers file data from NetApp ONTAP and other NAS and cloud storage using Transparent Move Technology.
- Analyze before you tier. Komprise Analysis indexes metadata across NetApp and other storage into the Global Metadatabase, shows how much data is cold by age, type, owner, and share, and models the savings for each object or cloud destination. The Komprise Flash Stretch assessment applies this analysis to identify how much primary flash capacity you can free.
- Tier whole files transparently. Transparent Move Technology moves cold files to object storage in their native format and leaves a transparent link at the source, so users and applications access files exactly as before. There is no rehydration penalty, and Transparent Move Technology cuts storage costs by 70% or more.
- Keep tiered data usable. Because files land in the object store as files, you access them directly with cloud-native analytics and AI services. Deep Analytics finds the exact files you need, and Smart Data Workflows deliver them to downstream AI and analytics tools without recalling them to primary storage.
- Refresh storage without recall. Tiered files do not depend on the source array, so a storage refresh or vendor change migrates only the active data. Elastic Data Migration moves the rest, with 27X faster NFS migrations and 25X faster SMB migrations using Komprise Hypertransfer.
Here is a summary of file-level tiering benefits over native NetApp tiering, including ransomware protection with object-locked tiered data:
| Evaluation Criteria | FabricPool Block Tiering | With Komprise |
|---|---|---|
| What moves | Cold blocks inside the array | Whole cold files |
| Object store format | ONTAP objects, readable only through ONTAP | Native files, readable without the source array |
| Storage coverage | NetApp ONTAP only | NetApp plus other NAS, cloud, and object storage |
| Policy basis | Per-volume policy and block inactivity | File age, access, type, owner, and share |
| Visibility before tiering | Array capacity and temperature | Global Metadatabase index with savings modeled by destination |
| Rehydration penalty | Recall needed for refreshes, migrations, and full-file reads | None; Transparent Move Technology keeps files usable |
| Backup footprint | Unchanged | Reduced; tiered files leave the backup set |
| Storage refresh | All tiered blocks recalled first | Only active data migrates |
| Cloud AI access | Requires recall and copy | Direct access to tiered files |
| Flash price exposure | Savings eroded by recalls and egress | 70%+ lower storage costs with no recall |
Frequently Asked FabricPool Questions
What is FabricPool?
FabricPool is a NetApp ONTAP feature that automatically tiers cold data blocks from an all-flash tier to lower-cost object storage on premises or in the cloud. ONTAP treats both tiers as one pool and moves blocks based on how long they have been inactive and the tiering policy set on each volume. Because it tiers blocks rather than files, the tiered data is readable only through ONTAP.
What is the difference between block-level tiering and file-level tiering?
Block-level tiering, used by FabricPool, moves inactive blocks of data from inside the storage array to object storage and needs the array to reassemble them. File-level tiering moves whole files, keeps them in their native format at the destination, and leaves a transparent link at the source. File-level tiering keeps tiered data usable without the original array, which removes the rehydration penalty during migrations, backups, and cloud access. For more detail, see Block Storage and Storage Tiering.
Does FabricPool have a rehydration penalty?
Yes. Blocks tiered by FabricPool are stored in an ONTAP format, so any operation that needs the full dataset outside the array requires ONTAP to recall them first. Storage refreshes, vendor changes, cloud migrations, and tools that read whole files trigger that recall. Each recall adds cloud egress and retrieval charges, consumes flash capacity, and extends project timelines.
Why is intelligent tiering more important as flash and SSD prices rise?
Gartner projects a 130% increase in combined DRAM and SSD prices by the end of 2026, so every terabyte of cold data kept on flash costs more each quarter. More than 70% of unstructured file data is cold, which makes tiering the fastest way to free flash capacity without buying more. Intelligent tiering uses analytics on file age, type, owner, and usage to decide what moves, works across storage vendors, and keeps tiered data accessible, so the savings hold through backups, refreshes, and migrations.
Can I use FabricPool tiered data for AI or cloud analytics?
Not directly. FabricPool writes blocks to the object store, not files, so cloud AI services, data lakes, and analytics platforms cannot read the tiered data from the bucket. The data has to be recalled through ONTAP and copied out first. File-level tiering stores whole files in native format, so you point cloud services at the tiered files directly and use them for AI, search, and analytics.
How does Komprise tier NetApp data without a rehydration penalty?
Komprise Intelligent Data Management uses Transparent Move Technology to tier whole files from NetApp ONTAP and other NAS systems to any object or cloud storage in native format. A transparent link at the source keeps access unchanged for users and applications, and the tiered files remain readable at the destination without the source array. Customers cut storage costs by 70% or more, and backup and refresh projects no longer require recalling tiered data. Komprise first shows how much NetApp data is cold and models the savings before anything moves. Learn more about a Storage Refresh Assessment.