Enterprise RAID Controller Recovery
HPE ProLiant Smart Array Data Recovery
We recover data from failed HPE ProLiant servers by extracting member drives, imaging them with PC-3000 through SAS HBAs, and reconstructing the array from HP's proprietary metadata on GPT Partition 9. P408i-a, P440ar, E208i-a, MR416i-p, and legacy P420i/P440ar controllers. Free evaluation. No data = no charge.
How Smart Array Controllers Fail and How We Recover Them
HPE ProLiant servers use Smart Array RAID controllers to manage arrays of SAS or SATA drives. When the controller fails, firmware corrupts, the Flash-Backed Write Cache (FBWC) battery dies, or enough member drives degrade to exceed parity tolerance, the logical drives go offline and the server cannot boot. Recovery requires extracting every member drive, imaging them independently through SAS HBAs with PC-3000, parsing HP's proprietary RAID metadata from GPT Partition 9, and reconstructing the array offline without relying on the original controller.
Smart Array controllers differ from Dell PERC and Broadcom MegaRAID in how they store on-disk metadata. HP reserves a hidden GPT Partition 9 on each member drive for RAID configuration data. This partition contains the drive ordering, stripe size (HP defaults to 256KB), parity rotation scheme, and logical drive boundaries. Standard Linux mdadm or generic RAID destriping software cannot parse this format. PC-3000 Portable III includes a dedicated HP Smart Array module for reading this metadata.
Smart Array Controller Generations
HPE has shipped multiple controller families across ProLiant generations. Each has a different cache architecture, interface capabilities, and failure characteristics that affect the recovery approach.
| Controller | Interface | Cache | ProLiant Generations | Recovery Notes |
|---|---|---|---|---|
| P408i-a SR Gen10 | 12Gb/s SAS | 2GB FBWC (flash-backed) | DL360 Gen10, DL380 Gen10, ML350 Gen10 | Standard GPT Partition 9 metadata. FBWC survives power loss via supercapacitor flush. |
| P440ar Gen9 | 12Gb/s SAS | 2GB FBWC (flash-backed) | DL360 Gen9, DL380 Gen9, ML350 Gen9 | POST Error 313 risk. Pre-v6.60 firmware sets persistent NVRAM disable flag on battery failure. |
| E208i-a SR Gen10 | 12Gb/s SAS (Mixed Mode) | No write cache | DL325 Gen10, DL360 Gen10 (entry) | No cache trapping risk. Software RAID mode (HBA mode) bypasses controller metadata entirely. |
| MR416i-p Gen11 | PCIe Gen4 Tri-Mode (SAS/SATA/NVMe) | 8GB cache (supercapacitor-backed) | DL360 Gen11, DL380 Gen11, DL380a Gen11 | Broadcom MegaRAID architecture. SPDM hardware root of trust limits chip-off on NVMe SEDs. |
| P420i / P440ar (Legacy) | 6Gb/s or 12Gb/s SAS | 512MB-2GB BBWC or FBWC | DL380p Gen8, DL360p Gen8, ML350p Gen8 | Older BBWC uses battery; battery degradation is the primary cache failure mode on Gen8 servers. |
GPT Partition 9: HP's Proprietary RAID Metadata
Every drive managed by an HP Smart Array controller contains a hidden GPT Partition 9 reserved for RAID configuration metadata. This partition is not visible to the operating system and is not listed in standard partition management tools. The controller reads this partition at boot to determine which drives belong to which logical drive, the stripe size, RAID level, parity rotation pattern, and the order in which drives should be assembled.
When drives are removed from an HP ProLiant and inserted into a different server or connected to a standard HBA, the operating system sees GPT partitions 1 through 8 (OS data) and partition 9 (HP metadata). Attempting to mount or modify partition 9 will corrupt the RAID configuration. During recovery, we read partition 9 in raw mode using PC-3000 Portable III's HP Smart Array module to extract the metadata without modifying it.
- Stripe Size
- HP Smart Array defaults to 256KB stripe size, four times larger than Dell PERC's default of 64KB. Misidentifying the stripe size during reconstruction produces apparently valid but irreversibly scrambled output. The metadata on GPT Partition 9 records the exact stripe size the administrator selected during array creation.
- Parity Rotation
- HP implements left-symmetric parity rotation by default for RAID 5 and RAID 6. The metadata specifies the rotation algorithm and starting position. Using the wrong rotation pattern during reconstruction produces silently corrupted data that passes surface-level filesystem checks but contains byte-level errors in file contents.
- Drive Ordering
- The metadata maps physical slot numbers to logical member positions. If an administrator moved drives between bays during the server's lifetime, the physical-to-logical mapping may not follow sequential slot order. The GPT Partition 9 metadata records the actual mapping regardless of physical position.
FBWC and BBWC Cache Failure Modes
HP Smart Array controllers use write-back caching to accelerate I/O. Writes are acknowledged to the host OS before being committed to disk. The uncommitted data sits in volatile cache memory protected by either a battery (BBWC on Gen8 and earlier) or supercapacitors with flash backup (FBWC on Gen9 and later). Cache failure is the most common source of data discrepancy between what the OS expects and what actually resides on the member drives.
BBWC (Battery-Backed Write Cache)
Gen8 and earlier P-series controllers (P420i, P222, P410i) use a lithium-ion battery module to maintain the DRAM write cache during power loss. The battery has a limited charge cycle lifespan, typically 3-4 years. Once the battery can no longer hold charge, the controller disables write-back caching and switches to write-through mode. If the battery fails while the cache contains unflushed writes and the server loses power simultaneously, those writes are lost.
- Failure indicator: iLO event log shows "Cache battery charge below threshold." POST warning appears but server continues booting.
- Data risk: Writes acknowledged to the OS but not committed to disk are lost if power fails during the battery degradation window.
FBWC (Flash-Backed Write Cache)
Gen9 and Gen10 P-series controllers (P440ar, P408i-a, P816i-a) replaced the battery with supercapacitors and a NAND flash module. During power loss, the supercapacitors provide enough energy to flush the DRAM cache contents to the flash module. On next boot, the controller reads the flash module and replays the cached writes to disk before the array comes online.
- Failure indicator: POST Error 313 on P440ar (Smart Storage Battery failure). The controller disables the cache permanently until the battery module is replaced.
- Data risk: If the server lost power while the FBWC contained dirty writes and the supercapacitor did not have enough charge to complete the flush, unflushed writes are trapped in the flash module. The array metadata on disk is stale.
POST Error 313: Smart Storage Battery Failure
POST Error 313 is specific to HP Gen9 servers with P440ar controllers. The error fires when the Smart Storage Battery can no longer maintain sufficient voltage to guarantee a cache flush during power loss. The controller permanently disables write-back caching to protect data integrity.
The complication arises with P440ar firmware versions earlier than v6.60. On these older firmware builds, the battery failure sets a persistent flag in the controller's NVRAM that survives battery replacement. Even after installing a new HPE 96W Smart Storage Battery (P/N 875241-B21 or 871264-001), the controller may refuse to re-enable write-back caching because the NVRAM flag is still set. The server continues running in write-through mode, but if the original power event already caused unflushed writes, the damage is done.
Replacing the battery does not recover trapped cache data. If the P440ar lost power while the FBWC held dirty writes, the battery replacement clears the POST error but does not replay the cached writes to disk. The on-disk array metadata reflects the pre-crash state; any writes that were acknowledged to the OS but not flushed are missing. Running consumer recovery software against the logical volume in this state captures the outdated stripe state, resulting in corrupted databases and virtual machines.
Our recovery protocol for Error 313 scenarios involves powering the FBWC module independently on the 0.02μm ULPA laminar flow bench and reading the pending writes directly from the flash-backed storage. We then reconcile those writes with the member drive images to produce a consistent array snapshot that reflects the state the OS expected before the crash.
Gen11 MR416i-p: Broadcom Tri-Mode and SPDM Limitations
HPE Gen11 ProLiant servers (DL360 Gen11, DL380 Gen11) replaced the traditional Smart Array controller with the MR416i-p, a Broadcom MegaRAID controller running HPE-branded firmware. The MR416i-p supports PCIe Gen4 Tri-Mode operation, meaning it can manage SAS, SATA, and NVMe drives simultaneously on the same backplane. This is a fundamental architectural change from the P-series controllers.
The MR416i-p uses the Broadcom on-disk metadata format (DDF-based), not HP's GPT Partition 9 format. Recovery tools that parse HP Smart Array metadata cannot read MR416i-p arrays. PC-3000 Portable III uses its Broadcom MegaRAID module for these controllers.
SPDM and Self-Encrypting Drives: The MR416i-p implements the DMTF Security Protection Data Model (SPDM) to establish a Hardware Root of Trust (HWRoT) with the iLO 6 baseboard management controller. When Self-Encrypting Drives (SEDs) are connected via the NVMe Tri-Mode interface, cryptographic keys are bound to this hardware trust chain. Direct NAND chip-off from these drives is not possible because the data encryption key is tied to the specific controller and iLO pairing. Recovery of physically failed NVMe SEDs requires component-level board repair of the original controller to restore the key chain.
For MR416i-p arrays using non-SED drives (standard SAS or SATA without hardware encryption), the recovery process follows standard Broadcom MegaRAID methodology: extract drives, image through SAS HBAs, parse the DDF metadata, and reconstruct the array offline. The Tri-Mode interface does not affect the recovery process once drives are removed from the chassis and connected directly to an HBA.
RAID Rebuild Risks on Degraded Smart Array Controllers
When a Smart Array controller reports a degraded RAID 5 array and prompts "Ready for Rebuild," initiating the rebuild risks destroying data that could otherwise be recovered. The rebuild process reads every sector of every surviving member drive to regenerate the missing parity or data blocks onto a hot spare.
- The surviving drives are already stressed. If one drive failed due to mechanical degradation (bearing wear, head instability), the remaining drives in the same server have similar runtime hours. They are statistically likely to develop Unrecoverable Read Errors (UREs) under sustained sequential load.
- A single URE halts the rebuild. When the controller encounters a read error on a surviving member during parity regeneration, it drops that drive from the array. A RAID 5 array that was already degraded by one drive is now missing two drives, which exceeds the single-parity tolerance. The logical drive goes offline.
- The rebuild partially overwrites parity data. Before the second failure halts the process, the controller has already written new parity blocks to the hot spare. The original parity data on the failed drive is needed to reconstruct the missing data, but the hot spare now contains partial parity from the incomplete rebuild. The original stripe map is no longer recoverable from the parity alone.
Power down the server. Do not initiate a rebuild on a degraded array. Image all member drives offline with write-blocking hardware before attempting any reconstruction. We recover degraded arrays by working from drive images, never from live arrays where a rebuild might trigger cascading failures.
Recovery Methodology for ProLiant Smart Array Servers
1. Controller and Array Evaluation
We identify the Smart Array controller model, firmware version, RAID level, number of logical drives, and current controller status (POST errors, cache state, drive bay status). If the iLO management interface is accessible, we export the Smart Storage Administrator configuration and event log before extracting drives. If the server is non-functional, we extract the configuration from GPT Partition 9 metadata after imaging.
2. Drive Extraction and Slot Documentation
Every drive is labeled by bay number, model, serial number, and firmware revision before removal. Smart Array controllers map drives to logical groups by physical bay position. If the bay mapping is lost, reconstruction requires testing all possible member permutations against the GPT Partition 9 metadata on each drive to identify the correct assembly order.
3. SAS Imaging with PC-3000
Each drive is connected to our imaging workstation through SAS HBAs. PC-3000 images the full LBA range, including the reserved GPT Partition 9. Enterprise SAS 10K/15K drives average 150-200MB/s throughput. Drives reporting SMART threshold warnings are imaged with adaptive retry parameters and selective head maps. Mechanically failed SAS drives receive donor head swaps on the 0.02μm ULPA laminar flow bench before imaging.
4. Metadata Parsing and Array Reconstruction
PC-3000 Portable III reads GPT Partition 9 from each member drive image to extract stripe size, parity rotation, drive ordering, and logical drive boundaries. For P-series controllers, the HP Smart Array module automates this parsing. For MR416i-p controllers, the Broadcom MegaRAID module reads the DDF metadata. Parity data from surviving members reconstructs any unreadable sectors from failed drives.
5. Filesystem Extraction and Delivery
The reconstructed logical drive is mounted read-only. Common filesystems on ProLiant servers include NTFS/ReFS (Windows Server), VMFS (for VMware ESXi datastores), ext4/XFS (Linux), and Hyper-V .vhdx files. We extract the target data, verify file integrity against the customer's priority list, and deliver on encrypted media.
ProLiant Smart Array Recovery Pricing
Smart Array recovery follows the same transparent pricing model as every other service: per-drive imaging based on each drive's condition, plus a reconstruction fee per logical drive. No data recovered means no charge.
| Service Tier | Price Range (Per Drive) | Description |
|---|---|---|
| Logical / Firmware Imaging | $250-$900 | Drives with firmware corruption, SMART threshold warnings, or cache desynchronization from Error 313 events. Most healthy SAS drives from ProLiant arrays fall in this tier. |
| Mechanical (Head Swap / Motor) | $1,200-$1,50050% deposit | Donor SAS heads matched by model, firmware revision, head count, and preamp version. Required for SAS drives with mechanical failure in ProLiant chassis. |
| Array Reconstruction | Calculated feeper logical drive | GPT Partition 9 metadata parsing, Smart Array or MegaRAID reconstruction, parity recalculation, and filesystem extraction. One fee per logical drive group. |
No Data = No Charge: If we recover nothing from your ProLiant array, you owe nothing. Free evaluation, no obligation.
Where Smart Array Geometry Actually Lives Across Three Generations
HP's on-disk RAID metadata has moved three times in twenty-five years. Recovery methodology depends on knowing which generation you are working with, because the parser you point at the drive images has to look in the right place.
| Controller Family | Metadata Location | Format | Offline Parser |
|---|---|---|---|
| Compaq Smart Array (5300, 6400, P600, MSA1000) | Reserved Information Sector at start of LBA | Proprietary RIS block, replicated across members | Manual hex parsing of the RIS block against the raw drive image |
| Smart Array Gen8-Gen10 P-series (P410, P420, P440ar, P408i-a, P822, P816i-a) | Hidden GPT Partition 9 at end of LBA address space | HP proprietary descriptor: stripe size, parity rotation, drive UUID, member order | PC-3000 Portable III HP Smart Array module |
| Gen11 MR416i-p (Broadcom MegaRAID rebadged with HPE firmware) | End-of-disk reserved area, not GPT Partition 9 | Broadcom Disk Data Format (DDF) per SNIA spec | Broadcom MegaRAID module, not the HP Smart Array module |
The practical consequence: a recovery shop that points the HP Smart Array parser at a Gen11 DL380 will find no valid metadata and report the array unrecoverable. The drives are fine; the parser is wrong. The original HP controller is not required for any of these three generations. Geometry parses from the drive images on the workstation.
RAID 5 and RAID 6 Rebuild URE Math on HP P-series
Enterprise SAS drives quote a non-recoverable read error rate of approximately one URE per 1015 bits, roughly one URE per 125 TB read. The HP Smart Array controller does not get an exception to this number. When a degraded RAID 5 enters Interim Recovery Mode and the operator inserts a replacement drive, the controller must read every sector of every surviving member to regenerate the missing data.
The probability of hitting at least one URE during a read of N bits is the binomial complement: P(URE) = 1 minus (1 minus E) raised to the N, where E is the per-bit error rate (approximately 10-15 for enterprise SAS).
Worked example. Eight 10 TB SAS drives in RAID 5 with one drive failed. The rebuild reads 70 TB across the seven survivors, which is roughly 5.6 times 1014 bits. At an NRRE of 10-15, P(URE) lands near 42 percent. Push the array to RAID 6 with twelve 16 TB drives and the rebuild read budget more than doubles; the URE probability climbs accordingly.
When the Smart Array controller hits a URE during rebuild, it stops. The controller marks the surviving drive that emitted the read error as failed, drops the logical drive offline with POST Error 1784 or 1786, and writes a failure flag to the metadata of the affected member. The array is now down two drives. RAID 5 single parity tolerance is exceeded. The hot spare contains partial parity from the aborted rebuild, which contaminates the stripe map.
The forensic imperative is unambiguous: never let the HP controller run a rebuild on an array that is candidate for recovery. Image every member offline with DeepSpar Disk Imager or ddrescue multipass, parse GPT Partition 9 against the static images, and reconstruct the array in software using PC-3000 Portable III. UREs encountered during imaging can be retried, mapped, and worked around; UREs encountered mid-rebuild crash the array.
POST Codes You Will See During Recovery Triage
The Smart Array Option ROM emits a specific POST code for each metadata-level event. Most of these are recoverable if no one presses a key. The codes below cover the events that frequently land servers in our queue.
- POST 1779: Replacement drive(s) detected or previously failed drive(s) now appear operational
- The controller saw a drive it previously marked failed, or a raw drive inserted while power was off. POST halts at an F1/F2 prompt. F1 disables the logical drives. F2 accepts the configuration and brings the array online; on a still-degraded RAID 5 this can initiate background parity calculations that overwrite recoverable user data. The safe action with data at stake is to leave the prompt, power down, and image the drives.
- POST 1785: Drive Array Not Configured
- The controller queried the members but could not assemble a valid geometry. Either GPT Partition 9 is corrupt on enough members, or too many member drives are missing or have failed simultaneously (two dead in a RAID 5, both sides of a RAID 1 mirror). The array is reconstructable offline from drive images.
- POST 1786: Drive Array Recovery Needed
- The logical drive is degraded. A member is failed or missing and fault tolerance is compromised. Operating in this state with the controller online risks a secondary URE crashing the entire array. Treat 1786 as a stop-and-image event, not as a prompt to install a hot spare.
- POST 1727: New (or previously failed) logical drive attachment detected
- The controller detected a logical array that was not present on the previous boot, or found conflicting metadata suggesting an improper migration between controllers. Accepting the auto-config offer can rewrite Partition 9 on the new members. Do not press a key. Pull the drives and image them.
Transportable Arrays and the Limits of HP Auto-Import
Because Smart Array geometry lives on the member drives (RIS on legacy, Partition 9 on Gen8-Gen10, Broadcom DDF on Gen11), HP arrays are physically transportable between chassis. Unlike Dell PERC, which requires the operator to explicitly Import Foreign Configuration from the controller BIOS, an HP Smart Array auto-detects the array on boot by scanning Partition 9, matching UUIDs across members, and presenting the logical drive to the OS. SSACLI shows it as an operational array.
The auto-import behavior masks three real limits that matter for recovery.
- Forward generational migration works. Moving drives from a P410 (Gen8) to a P440ar (Gen9) or P408i-a (Gen10) usually succeeds. The newer firmware recognizes the older metadata revision and imports the array.
- Backward migration fails silently. Drives from a Gen10 P408i-a placed in a Gen8 P410 will not import. The older firmware cannot parse the newer Partition 9 schema. The controller may offer to initialize the drives, which would destroy the array.
- Migration to Gen11 MR416i-p categorically fails. The MR416i-p is Broadcom MegaRAID. Its DDF parser scans the end-of-disk reserved area and does not look at Partition 9. Any Gen8-Gen10 array moved onto an MR416i-p reports no valid configuration. The reverse is equally true: Gen11 DDF metadata is invisible to the HP Smart Array parser on a Gen10 P408i-a.
The operational rule that follows from this: if you are evacuating drives from a dead ProLiant into a working donor server to read the data, the donor controller must be the same generation or one step newer in the same controller family. Crossing the P-series to MR-series boundary requires offline reconstruction against drive images, not a chassis swap.
HP ProLiant Smart Array Recovery; Common Questions
Why does HP Smart Array recovery differ from Dell PERC recovery?
My ProLiant shows '1785 - Drive Array Not Configured' at POST. What happened?
The P408i FBWC module shows 'Cache Temporarily Disabled.' Does that affect recovery?
What is POST Error 313 on a P440ar, and can you recover the data?
How much does HP Smart Array recovery cost?
Do you support the Gen11 MR416i-p controller?
What does POST Error 1779 mean on an HP ProLiant?
Can I move HP Smart Array drives from a P410 to a P440ar?
Does an HPE Smart Storage Battery failure mean my data is lost?
Why won't generic RAID destriping software rebuild my HP array?
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