>>>> 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. - Grant
