Disk drives supported include 512n (Standard) format, 512e format, and Advanced 4K Native format with sectors, as follows:

Format	Physical Sectors	Logical Sectors
512n (Standard)	512B	512B
512e	4KiB	512B
Advanced 4K Native	4KiB	4KiB

Stratus recommends using disks with the 4K sector size for better performance. everRun systems support 4K sector size disks in native mode. When using 4K storage, observe the following restrictions:

• Each storage group must contain logical disks of the same or compatible disk types:
  • A storage group with the 512n disk type supports logical disks with the 512n or 512e disk type.
  • A storage group with the 512e disk type supports logical disks only with the 512e disk type.
  • A storage group with the 4K disk type supports logical disks only with the 4K disk type.

  For example, you cannot add a disk with the 4K logical disk disk type to a storage group with the 512n or 512e disk type.

• The disk type of the Initial Storage Group is automatically defined by the disk type of the boot disk in the first PM on which you install the everRun software: the 4K disk type for a 4K boot disk, or the 512n disk type for a 512n or 512e boot disk. The boot disk in the second PM must be the same disk type. You cannot change the disk type of the Initial Storage Group after the software installation.
• You can set the disk type for other storage groups only when you create each storage group and select its Disk Type (as described in Creating a New Storage Group). You cannot change the disk type of an existing storage group; you would need to create a new storage group and select the new disk type.

• Because the disk type of a storage group affects the sector size of your VM volumes, it is important to plan your storage groups carefully:

  • A storage group with the 512n or 512e disk type provides the sector size of 512B for its VM volumes.
  • A storage group with the 4K disk type provides a sector size of either 4K or 512B, selectable for each of its VM volumes.
  • If a storage group with the 512e or 4K disk type provides a volume with the 512B sector size, it is presented to the VM as a volume with the 512e disk type.

  Note that the boot volume for each VM must be 512B, regardless of the storage group's disk type. Only data volumes can use the 4K sector size. Ensure that your guest operating systems support 4K volumes before creating or attaching them.

In addition, note the following restrictions of the Initial Storage Group:

• If you add a second logical disk to the default Initial Storage Group, its size must be greater than 32.2GB.

• everRun software prevents all non-volatile memory express (NVMe) devices from being included in the Initial Storage Group because not all BIOS and UEFI systems allow NVMe devices to be bootable devices.

When planning your system configuration, confirm that your storage configuration meets these requirements and then return to Site and System Preparation.