Storage Requirements
An everRun system has the following storage requirements and recommendations:
- Each physical machine must contain at least two physical disks.
- Stratus strongly recommends that your system use a storage RAID controller.
- If the system has a single logical disk, Stratus strongly recommends that you configure the RAID controller so that logical disks presented to the host are backed by redundant physical drives.
- Stratus strongly recommends that RAID controllers have a battery-backed write cache.
- You must configure the RAID controller to boot off the first logical disk.
You must use the tools supplied by the RAID controller vendor to monitor the health and status of individual physical disks in a RAID set. The everRun software does not monitor the state of physical disks in a RAID set.
Disk drives supported include Standard format, 512e format, and Advanced 4K Native format with sectors, as follows:
| Format | Physical Sectors | Logical Sectors |
|---|---|---|
|
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 sector size. For example, you cannot add a 4K logical disk to a 512B storage group.
- The sector size of a storage group is automatically defined by the sector size of the first logical disk that you add to the group. After the sector size of the storage group is set, you cannot change it. You would need to create a new storage group with logical disks of the new sector size.
-
Because the sector size 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 512B sector size supports only 512B VM volumes.
- A storage group with the 4K sector size supports 4K or 512B VM volumes.
Note that the boot volume for each VM must be 512B, regardless of the storage group's sector size. 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.