Re: [gentoo-user] Rename /dev/nvme0n1 to /dev/sda

[Grant <emailgrant@gmail.com>]

>>>>>> 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