>>>>>> My new laptop uses /dev/nvme0n1 instead of /dev/sda which conflicts >>>>>> with the script I use to manage about 12 similar laptops running >>>>>> Gentoo. Is there a udev method for renaming the disk that will work >>>>>> well with any USB disks that happen to also be attached? >>>>> >>>>> I'm not certain what you mean by that, but I would guess that you want >>>>> the nvme disk to show up as /dev/sda, and the USB disk(s) to show up >>>>> as /dev/sd[b-z]. >>>>> >>>>> It is not possible to accomplish this using udev; the kernel owns the >>>>> /dev/sdX device namespace, and will sequentially create devices nodes >>>>> for SCSI-like block devices using that namespace. There is no way to >>>>> change that using a udev rule. >>>> >>>> >>>> Can I rename /dev/sda to /dev/sd[b-z] if it's attached via USB, and >>>> then rename /dev/nvme0n1 to /dev/sda if /dev/nvme0n1 exists? >>>> >>>> Alternatively, can I rename /dev/sda to /dev/sd[b-z] if /dev/sda and >>>> /dev/nvme0n1 exist, and then rename /dev/nvme0n1 to /dev/sda if >>>> /dev/nvme0n1 exists? >>> >>> You might technically be able to do it, but I would guess it would >>> cause some nasty race conditions between the kernel and udev. It's a >>> bad idea. >> >> >> Is it the conditionals that cause this to be a bad idea? Because I >> believe udev has functionality designed to rename devices exactly like >> this. > > udev doesn't provide any functionality to rename device nodes. You can > adjust their permissions, and create symlinks, but there is no direct > way to rename them.
I use stuff like this to rename my USB devices and it works perfectly: SUBSYSTEM=="net", ACTION=="add", ENV{ID_NET_NAME_PATH}=="enp0s20u2u1", NAME="net0" Isn't this a true rename of the device node? - Grant