# Dell - Hard Drive Capacity Difference Between Drives

The capacity difference between the two drives is caused by **differing logical block/sector formatting** or **OEM vendor provisioning (HPA / Max LBA limits)**.

Even within the same Western Digital / Ultrastar DC HC520 12TB family, SAS drives are deployed with different low-level format structures:

### 1. Different Sector Formats (512e vs. 4Kn vs. Enterprise 520/528 Bytes)

- **Standard 12TB:** Typically reports around **11,175.5 GB** (<span class="math-inline" data-index-in-node="53" data-math="11.17\text{ TiB}">$11.17\\text{ TiB}$</span>) when formatted with standard 512-byte emulation (`512e`) or 4096-byte native (`4Kn`) sectors.
- **Enterprise SAN/EMC Formats:** <span class="citation-2">Drives pulled from proprietary SAN enclosures (EMC, NetApp, Huawei) often use </span>**<span class="citation-2">520-byte or 528-byte sectors</span>**<span class="citation-2 citation-end-2"> (or Type 1/2 Data Integrity Field protection).<sup class="superscript" data-turn-source-index="1"></sup></span> When translated or truncated by a Dell PERC/HBA, the usable LBA count drops, showing up around **10,948.5 GB**.

### 2. OEM Firmware &amp; Provisioning (HPA / Max LBA)

If one drive came from an OEM vendor (e.g., NetApp, EMC, Cisco, HPE) and the other is a generic Dell/retail drive, the OEM firmware may restrict the drive's total accessible Logical Block Addressing (LBA) count via Host Protected Area (HPA) or factory provisioning.

### How to Fix / Match Them

To get disk `0:1:3` to match `0:1:4` at full capacity:

1. **Check the Sector Size:**
    
    Boot into a Linux live environment (or pass the drive through via HBA/IT-mode) and run:
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-28 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="31" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-28"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-28"><div _ngcontent-ng-c3183803001="" class="code-block-decoration header-formatted gds-emphasized-body-m ng-tns-c3183803001-28 ng-star-inserted"><span class="ng-tns-c3183803001-28">Bash</span><div _ngcontent-ng-c3183803001="" class="buttons ng-tns-c3183803001-28 ng-star-inserted"><button aria-label="Download code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button><button aria-label="Copy code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button></div></div></div></div></div>```
    smartctl -i /dev/sdX
    # or
    sg_scan -i
    ```
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-28 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="31" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-28"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-28"></div></div></div>Check the `Logical block size` and `Formatted with type 1/2/3 protection` values.
2. **Low-Level Format to Standard 512e / 4Kn:**
    
    Using the `sg3_utils` package in Linux, reformat the drive to standard 512-byte or 4096-byte sectors:
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-29 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="34" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-29"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-29"><div _ngcontent-ng-c3183803001="" class="code-block-decoration header-formatted gds-emphasized-body-m ng-tns-c3183803001-29 ng-star-inserted"><span class="ng-tns-c3183803001-29">Bash</span><div _ngcontent-ng-c3183803001="" class="buttons ng-tns-c3183803001-29 ng-star-inserted"><button aria-label="Download code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button><button aria-label="Copy code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button></div></div></div></div></div>```
    # Reformat to standard 512-byte sectors:
    sg_format --format --size=512 /dev/sdX
    ```
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-29 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="34" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-29"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-29"></div></div></div>*(Note: This is a low-level format that will erase all data on that specific disk and takes several hours for a 12TB drive.)*
3. **Reset Max LBA (if sector size is already 512):**
    
    If the drive was already 512 bytes, reset any HPA/LBA clamp:
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-30 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="37" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-30"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-30"><div _ngcontent-ng-c3183803001="" class="code-block-decoration header-formatted gds-emphasized-body-m ng-tns-c3183803001-30 ng-star-inserted"><span class="ng-tns-c3183803001-30">Bash</span><div _ngcontent-ng-c3183803001="" class="buttons ng-tns-c3183803001-30 ng-star-inserted"><button aria-label="Download code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button><button aria-label="Copy code" class="mdc-icon-button mat-mdc-icon-button mat-mdc-button-base mat-badge mat-unthemed mat-badge-overlap mat-badge-above mat-badge-after mat-badge-small mat-badge-hidden ng-star-inserted"></button></div></div></div></div></div>```
    hdparm -N /dev/sdX
    # To restore full native capacity:
    hdparm -N p[max_lba_value] /dev/sdX
    ```
    
    <div _ngcontent-ng-c3183803001="" class="code-block ng-tns-c3183803001-30 ng-animate-disabled ng-trigger ng-trigger-codeBlockRevealAnimation" data-hveid="37" jslog="223238;track:impression,attention;BardVeMetadataKey:[["r_5ecad10f5341abc6","c_4a4c7a6489319c2c",null,"rc_958598cce5520ab4",null,null,"en",null,1,null,null,1,0]]"><div _ngcontent-ng-c3183803001="" class="formatted-code-block-internal-container ng-tns-c3183803001-30"><div _ngcontent-ng-c3183803001="" class="animated-opacity ng-tns-c3183803001-30"></div></div></div>

Once reformatted, the Dell PERC controller will detect `0:1:3` at the full **11175.5 GB** size.