Seems odd, there are missing Raid levels. dont know the history of linux-raid changes log, but seems someone made a bad decision in the past. Let me explain: Enmotus FuzeDrive 1.6TB its actually a QLC 2TB M.2 NVMe PCIe that Requires Windows Raid drivers. Has built-in different technologies, All-in-one. #1. Smart Cache RAID mode... Small fast SSD + Larger HDD. Similar to intel Optane or Apple Fusion Drive, But both solid, smarter, defrag the ssd, moves most access files to Cache drive, and files with less access to Main/Large storage. #2. RAID2 mode. the drive is partitioned in 2. 1/4 of the 2TB QLC is used in Raid level=2 mode. The reason is to emulate an SLC with QLC. Increase speed & longevity by 4x By reducing size 1/4. Real SLC are very expensive & power hungry. QLC are cheap. Basically 2 Raids in 1. Inception. Linux-Raid, should have at least Raid level=2 To create SLC, MLC or TLC from QLC, TLC, MLC ssd drives. for example: Samsung 970 Pro is MLC "2-Bit" PCIe v3.0 Samsung 980 Pro is TLC "3-Bit" PCIe v4.0 Crucial MX500 is TLC, Crucial BX500 is QLC "4-Bit", No Dram. etc... Smart Cache Raid is interesting, But more complex, would requiere creating a second Journaled log file, or an enhanced version. Temp folders are usually better on Ram drives of 4GB. There is a ramdrive for linux, with Cache or Not, just drive. Called rapiddisk on github. By pkoutoupis But the lack of Raid level = 2 is devastating for Linux.
