and you shouldn't be using any of those, since the order can and will change. The numbers are based on the order the devices and device drivers are initialized in, not based on physical location in the system. The modern approach (assuming you're using udev) is to use the symlinks in /dev/disk/by-id/ or /dev/disk/by-uuid/ instead, since both are consistent across reboots (and by-id should be consistent across reinstalls, assuming the same partitioning scheme on the same physical drives)
This is also why Ethernet devices now have names like enp0s3 - the numbers are based on physical location on the bus. The old eth0, eth1, etc. could swap positions between Linux upgrades (or even between reboots) since they were also just the order the drivers were initialized in.
Well it's sdx because they both use the SATA interface. The sdx convention actually comes from scsi though, and the fact that SATA and USB drives use it might point to some code reuse, or maybe a temporary solution that never got fixed due to breaking backwards compatibility.
Fun fact: IDE drives use the hdx naming convention.
Namespaces are the construct in NVMe technology that hold user data. An NVMe controller can have multiple namespaces attached to it. Most NVMe SSDs today just use a single namespace, but multi-tenant applications, virtualization and security have use cases for multiple namespaces.
device v
/dev/nvme0n1p1 < partition
namespace ^
There are two types of people: Those who are able to identify gaps in their knowledge and actively seek to fill them... and whatever this meme is.
In short; sd stands for SCSI Disk and SSD and USB all use the SCSI protocol. While SD-cards/emmc (flash-on-CPU) are named emmcblkpX for emmc block device, partition X. And NVME have additionally namespaces, which is the nX part.
Back in the olden times the Linux kernel had a dedicated parallel-ATA subsystem with /dev/hda devices. It was then rolled up in to the scsi subsystem to simplify maintaining drivers (everything using the same library for disk access). I'm old :(
It's a lot better than the system that just randomly throws in your USB drives with your SCSI/SAS/SATA/PATA drives. Or the systems that calls everything a SCSI drive when it usually isn't a SCSI drive.
I will take a look at it, but the fundamental issue is it screws with the iommu groups too and then I have to go fix that in proxmox. If I can at least guarantee a network connection then I can remote in and fix it in the event something goes really wrong.