Scenario 1. StarWind VSAN shows an error “Can not store virtual disk with sector size 512 bytes on storage that uses 4k sector size” while creating Virtual Drives with 512 virtual block size on Hardware RAID array created and managed by Dell Perc 12 controllers;

Scenario 2. Virtual Disks created and managed by Perc 12 controllers are not shown in StarWind Controller Virtual Machines if PCI-E pass-through is used.


The Dell Perc 12 controllers are using a new generation of Broadcom SAS chips – SAS 4116W.

NOTE: Broadcom controllers with the 8th generation of SAS RAID-on-Chip (SAS4XXX) are also affected by this KB article.

In scenario 1 – Virtual Disks that are created with Dell Perc 12 controllers are exposed to the OS as 4k sector devices.

NOTE: StarWind VSAN can’t create 512 emulated virtual block devices on top of 4k physical block devices at this very moment.

In scenario 2 – Perc 12 drivers are available only for the most recent Linux OS and Linux Kernels.


For scenario 1 – not available at this very moment;

For scenario 2 – not available at this very moment.

NOTE: StarWind is aware of the issues with Perc 12 controllers and is working on their resolution.


For scenarios 1 & 2 – present the Perc 12 array as a single Eager-Zeroed Thick Provisioned VMDK to the StarWind Controller VM;

For scenario 1 – Switch the Perc 12 controller into HBA mode, pass drives into CVM, and use Linux software RAID (MDADM) instead of Perc 12 hardware RAID.

Note: Please consult StarWind Support if you have a valid support contract or your Account manager during the trial period.

Related information

  1. 4k VD block size –
  2. List of supported OSs –
  3. Scenario 1 and Scenario 2 will not affect Windows-based installations if Windows Server 2019/2022 is used in conjunction with StarWind Virtual SAN for Hyper-V.

Request a Product Feature

To request a new product feature or to provide feedback on a StarWind product, please send an email to and put “Product Feature Request” in the subject line.

Back to Knowledge Base