RAID Components

There are three major RAID logical components in SupremeRAID™, the  Physical Drive (PD) , the  Drive Group (DG) , and the  Virtual Drive (VD) .

Physical Drive (PD)

Since NVMe drives are not directly attached to the SupremeRAID™ controller, you must tell the controller which SSDs can be managed. Once an SSD has been created as a physical drive, the SupremeRAID™ driver unbinds the SSD from the operating system, meaning the device node (/dev/nvmeX) will disappear and is no longer accessible. At the same time, a corresponding device node is created (/dev/gpdX) by the SupremeRAID™ driver. You can check the SSD information, such as SSD model or SMART logs, using this device node. To control and access the SSD using /dev/nvmeXn1, you must first delete the corresponding physical drive.

Currently, SupremeRAID™ supports a total of  32  physical drives, regardless of whether the physical drives are created from a native NVMe SSD, a drive connected through NVMe-oF, or a SAS/SATA disk.

Drive Group (DG)

The main component of RAID logic is a RAID group. When the drive group is created, the SupremeRAID™ driver initializes the physical drives with the corresponding RAID mode to ensure that the data and the parity are synchronized. There are two types of the initialization processes.

• Fast Initilization: When all of the physical drives in the drive group (DG) support the deallocate dataset management command, the SupremeRAID™ driver performs fast initialization by default, meaning the drive group state is optimized immediately.
• Background Initialization: Performance will be slightly affected by the initialization traffic, but you can still create the virtual drive and access the virtual drive during a background initialization.

Currently, SupremeRAID™ supports a total of  8  drive groups, with a maximum of  32  physical drives in one drive group.

Virtual Drive (VD)

The virtual drive is equivalent to the RAID volume. You can create multiple virtual drives in the same drive group for multiple applications. The corresponding device node (/dev/gdgXnY) appears on the operating system when you create a virtual drive, and you can make the file system or running application directly on this device node. Currently, the SupremeRAID™ driver supports a maximum of  1023    virtual drives in each drive group.