On Sun, Sep 3, 2017 at 2:11 PM, Grant <emailgr...@gmail.com> wrote: >>> 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.