Arch Linux

stephano

Member

Registered: 2018-01-16

Posts: 3

Persistent block device naming confusion

After a standard installation following the installation guide I'm finding the documentation on persisting block device names a little confusing. This may simply be my lack of knowledge here, but perhaps there's also some room for documentation improvement.

Here's my path:

1. install using the installation guide
2. notice my block devices are randomly named ( /dev/sd* )
3. find the article specifically addressing this issue, and after reading the intro, follow the link to udev fixes:
https://wiki.archlinux.org/index.php/Pe … _with_Udev
4. follow the link in this section to udev documentation:
https://wiki.archlinux.org/index.php/Ud … vice_names
5. this seems promising, and mentions: "A udev rule can be added to use static device names." However, the article never goes on to explain how to do this. It then circles me back to the article on persistent block device naming.

I feel like at the end of this path I should have been given a paragraph on udev rules for block devices, much like video devices and printers on the udev page:
https://wiki.archlinux.org/index.php/Udev#Video_devices
https://wiki.archlinux.org/index.php/Udev#Printers

So am I missing something here?

phw

Member

Registered: 2013-05-27

Posts: 318

Re: Persistent block device naming confusion

The article you linked in 4. also links to https://wiki.archlinux.org/index.php/Pe … ice_naming

And this explains the available persistent names for block devices (UUID, label etc.). Usually those are sufficient and can be easily used where ever persistent names should be used.

For actually using udev to set custom names I could not find anything in the wiki

stephano

Member

Registered: 2018-01-16

Posts: 3

Re: Persistent block device naming confusion

I agree that page is very helpful overall, but for someone looking to use udev, there does seem to be a lack of info.

There are also links pointing back and forth between:

Persistent_block_device_naming#Static_device_names_with_Udev
and
Udev#Setting_static_device_names

I feel like these two articles should not be pointing to each other without some kind of actual udev fix.

Should I put in a documentation bug?

phw

Member

Registered: 2013-05-27

Posts: 318

Re: Persistent block device naming confusion

At least to me this looks like a documentation bug, yes. Unfortunately I also don't know how to do this with udev.

But it's probably worth pointing out that IMHO the installation instructions should focus on the predefined persistent naming schemes using UUIDs and labels. Those namings are also done with udev, but they are available by default and perfectly suited for setting up fstab, bootloader etc. Having entirely custom names is a rather specific need

stephano

Member

Registered: 2018-01-16

Posts: 3

Re: Persistent block device naming confusion

I completely agree. That is how I read the installation instructions, and it certainly made it easy to setup my various block devices.

The problem I originally ran into was that my block devices got named starting at /dev/sde rather than /dev/sda. The documentation makes me think I can fix this, but then falls a bit short.

I'll file a bug. I'm happy to help with wording once someone shows me how to do this in udev.

Last edited by stephano (2018-01-16 22:58:54)