When installing Windows Server 2008 or Windows Server 2008 R2 with or without Hyper-V, Hyper-V Server 2008 or Hyper-V Server 2008 R2, and HPC Server 2008 or HPC Server 2008 R2, the Windows Server installation failed with “The computer could not find a valid system volume” error message. The problem only arises when installing to previously used disks in ZFS pool.

Other symptoms of the issue including when using Diskpart with the clean or clean all command from within Windows to erase any existing partitions on a disk which was formerly used in a ZFS pool before creating Windows compatible partitions, the following error message may happen:

“The system’s information about the object may not be up to date.”

And, when in the Disk Management MMC console to try to online a disk which was formerly used in a ZFS pool, system may return the following error message:

“The disk structure is corrupted and unreadable.”

The cause for the Windows Server 2008 (R2) installation error is due to the EFI partition header size is 200H on disks using the ZFS filesystem. All versions and editions of Windows Server 2008 checks for an EFI partition header size of 5CH when examining disks, and thus the header size does not match the expected value, hence the setup wizard decides that the disk is corrupt. This leads to a situation where the ZFS disks cannot be onlined, and cannot be cleaned or repartitioned using diskpart directly.

The EFI partition information on the disk is not able to be reset from within Setup. To resolve the issue, following the resolution steps provided by KB2000301 when disk with problem attacked to a running Windows Server 2008 system.

  1. From a command prompt with administrative rights, run Diskpart.
  2. Issue the following commands (in Diskpart):

    SAN POLICY=OnlineAll

  3. Open Device Manager.
  4. Under Disk Drives, right click each disk (that has the problem) and choose Uninstall.
  5. Open Disk Management.
  6. Choose Rescan from the Action menu.
  7. Initialize each disk.
  8. The disks should now be useable. Continue to partition and format the disk as desired.