Hardware RAID Controller

My server (Dell PowerEdge R730) came equipped with a hardware RAID controller.
The model is Dell PERC H730.

Server Setup

When I initially set up my homelab using this server, I had a hard time figuring out why the Proxmox VE installer could not find any disks to install itself onto.

The solution I came up with for this was to go into the System Setup (F2 on boot), go to Device Settings, then go to the specific disks that I added and run the "Convert to non-RAID device" operation on each of them.

As I added more and more storage devices, this process got tiresome.

I decided to dig a bit deeper into how I might allow passthrough to bypass the hardware RAID controller entirely.

RAID Controller Modes

There are three main modes that a RAID controller can be set to.

1. RAID Mode
2. HBA Mode
3. JBOD Mode

The default configuration for the Dell PERC H730 (and likely many other systems' RAID controllers) is RAID mode.

RAID Mode

The default mode for the PERC H730 integrated RAID controller is RAID mode.

This mode allows the controller to aggregate disks into virtual RAID volumes, which effectively masks the individual disks themselves.

This mode is fine if we're opting for a hardware RAID configuration for our backup and striping disks.

However, if we want to use any of the advanced features of Proxmox by utilizing the all features of ZFS, or if we want to use software RAID via mdadm, this mode is not ideal.

Setting up a Hardware RAID Array

If we ever did want to set up a RAID array using the hardware RAID controller, this must be done during boot in the system setup.

We'd need to configure a RAID array using the RAID controller's setup utility (like the PERC configuration, typically accessed with Ctrl+R at boot time).

If we wanted to use hardware RAID for our Proxmox installation:

• Enter the RAID controller menu during boot and create the RAID array (RAID1, RAID5, RAID10, etc.).

• Save the RAID configuration and exit. The controller now exposes a single logical disk, which will be available to the OS.

• Boot into the Proxmox VE installer and select the RAID array we created as the installation target. This will be treated as any other storage device.

• Post-install, we can format and manage the logical disk with ext4, xfs, lvm, etc., but we won't have OS-level access to individual disks, nor can we use some of the more advanced features of ZFS, which require direct drive control.

• For monitoring or management, we would need to ensure the RAID controller drivers are loaded and compatible with Proxmox's kernel, to avoid possible detection issues.

  • Some controllers may require manual driver installation.

Keep in mind, hardware RAID abstracts away the physical disks. All disk management, redundancy, and failures are handled by the controller, not by Proxmox/Linux.

Also keep in mind, we lose access to features like ZFS or Ceph that require direct disk control and SMART data.

This approach is standard when using hardware RAID on Dell servers for Proxmox, but it's only really optimal if hardware RAID features (e.g., cache, BBU, redundancy) are required, and we don't need the advanced software RAID features of mdadm or ZFS.

Honestly...

Just use HBA/JBOD with software RAID via mdadm or ZFS.

HBA Mode

One of the options that I found was Host Bus Adapter (HBA) mode, which some hardware RAID controllers support.
This simply passes through physical drives directly to the operating system without aggregating them or masking them behind a RAID layer.

JBOD Mode

The other variant of HBA is "Just a Bunch of Disks" (JBOD) mode.
This mode denotes a configuration where each disk is presented individually, rather than part of a RAID array.

This mode is often used synonomously with HBA.

Each disk is seen by the OS as a separate storage unit, allowing direct access and management per disk.

Enabling HBA Mode

I found that the PERC H730 did support HBA mode, so I opted to enable that rather than the manual non-RAID device configuration.

HBA Mode on Other Models

I have not tested this process on other models of integrated hardware RAID controllers, as I do not have access to any other servers. However, I would assume this process is identical on other models put out in Dell PowerEdge series servers.

To enable HBA mode through the PERC H730 hardware RAID controller, we need to boot into the System Setup screen (F2 on boot).

From there, we navigate to:

• System Setup (Main Menu)

• Device Settings

  • Select the hardware RAID controller:

    Integrated RAID Controller 1: Dell PERC <PERC H730 Mini> configuration utility
    

• Controller Management

• Advanced Controller Management

At the bottom of this screen, there is an option to select: "Switch to HBA mode".

Select it and press Enter and we should get a message indicating the operation was successful.

From there, it's a simple reboot.

From now on, all disks that are connected to the server should be immediately available to the operating system directly.

This will allow us to utilize the disk hot-swap feature that these rack servers afford us as administrators.

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