IBM XIV Storage System Data Recovery
The IBM XIV Storage System is a grid-based block array acquired by IBM in 2008, built around a large number of standard modules rather than a conventional controller-and-shelf design. Its data distribution and mirroring scheme are unlike classic RAID, so a recovery evaluation has to reconstruct the grid's own placement logic rather than assume a familiar stripe layout.
Platform Lineage and Naming
XIV was originally developed by an Israeli storage start-up of the same name and acquired by IBM in 2008. IBM shipped it as the IBM XIV Storage System, with the Gen2 generation (machine types 2810/2812) followed by Gen3 (2812-114/214) adding solid-state caching and faster interconnects.
IBM positioned XIV as a high-throughput, easy-to-manage block platform for years before gradually moving customers toward FlashSystem. The architectural ideas behind XIV — large grids of commodity modules, pseudo-random data distribution and rapid rebuild — carried forward into the FlashSystem A9000 and A9000R, which combined a hyper-scale grid design with inline deduplication and MicroLatency flash modules.
- IBM XIV Storage System (Gen2, Gen3)
- Machine types 2810-A14, 2812-A14, 2812-114, 2812-214
- XIV Storage Software — the array's management and data-placement layer
- Successor architecture: IBM FlashSystem A9000 / A9000R (hyper-scale grid, inline dedup)
Generations and Models We Evaluate
| Generation / family | Models |
|---|---|
| Gen2 | 2810-A14, 2812-A14 — 15-module grid, up to 180 drives — original SATA-based generation |
| Gen3 | 2812-114, 2812-214 — added SSD caching and 10 GbE/InfiniBand interconnect options |
| Successor | FlashSystem A9000, A9000R — hyper-scale grid with inline deduplication, not a direct XIV upgrade path |
Architecture and Data Layout
An XIV system is built from interface modules, which handle host connectivity, and data modules, which hold the disks — all connected over an internal switched grid rather than a shared backplane. Every module runs the same XIV Storage Software and participates in both data placement and processing.
Data is broken into fixed 1 MB partitions and distributed pseudo-randomly across every disk in every data module, so a given logical volume has pieces scattered across the entire grid rather than sitting on a fixed set of drives.
In place of classic RAID, XIV mirrors each partition to a second copy held on a different module, and it rebalances and rebuilds automatically in the background after a drive or module failure, spreading the rebuild load across the whole grid rather than a small drive group.
Protocols and formats: Fibre Channel, iSCSI, SCSI-3 volume mapping
- Protection is by mirrored 1 MB partitions distributed pseudo-randomly across all data modules, not a RAID 5/6 stripe — reconstructing a volume means resolving the distribution table, not walking a fixed stripe width.
- Because partitions from every volume are interleaved across the whole grid, the loss of a data module affects a slice of many volumes simultaneously rather than one clearly bounded LUN.
- Automatic rebuild after a failure redistributes partitions across remaining modules, which changes the physical layout over time and must be accounted for when reconstructing an as-of-failure state.
Failure Scenarios
Logical failures
- Volume or storage pool deleted or reformatted
- Failed microcode/software upgrade on the XIV Storage Software
- Corrupted distribution or mirroring metadata after multiple module events
- Host file system or database corruption on presented volumes
- Mismanaged remote mirroring or snapshot restore
Hardware failures
- Multiple concurrent data module failures beyond the mirroring scheme's tolerance
- Interface module failure isolating access to the grid
- Internal switch/interconnect faults affecting module communication
- Multiple drive failures inside a single data module during an active rebuild
- Power or environmental events affecting the full grid
What Not To Do Before an Evaluation
- Do not run rebuilds, reconstructions or re-initialisations against an array that has already lost more drives than its protection level allows.
- Do not recreate pools, aggregates, disk groups, storage pools or clusters — these operations write new metadata over the structures a recovery needs.
- Do not swap drives between slots, and do not reorder shelves. Record the original slot and shelf positions before removing anything.
- Do not run file-system repair tools against production volumes before the underlying storage layer has been evaluated.
- Do not restore a backup or replication set over the affected volumes until the recovery scope has been assessed.
- Do not eradicate deleted volumes or empty recycle/destroyed states on platforms that hold deleted data for a retention window.
Our Evaluation and Recovery Process
- Intake and platform identification — array model, generation, firmware, protection layout and the sequence of events that led to the failure.
- Read-only evaluation of the media and array structures, including assessment of drive health and the extent of any physical damage.
- Forensic imaging of all contributing media, with cleanroom work where drives require it. Originals are preserved unaltered.
- Reconstruction of the storage layer — pools, aggregates, parity groups, chunklets, extent groups or objects — from the images.
- Extraction of the layers above: file systems, virtual machines, databases, mailboxes and shares.
- Verification against a file list and customer-nominated critical data, followed by secure return on encrypted media.
Frequently Asked Questions
Is XIV protected by RAID?
No. XIV protects data with mirrored 1 MB partitions distributed pseudo-randomly across all data modules, which behaves differently from a RAID 5/6 group during failure and rebuild.
What happens if a data module fails?
The grid rebuilds affected partitions automatically from their mirrors, drawing on the whole system's spare capacity — but if a second related failure occurs before rebuild completes, an evaluation is needed to determine what can be reconstructed.
Is FlashSystem A9000 the same architecture as XIV?
It is a related design lineage — a hyper-scale grid with inline deduplication — but it is a distinct platform from XIV rather than a simple hardware refresh.