Re: [gentoo-user] help with Persistent hard disk device names with udev

[Matthias Schwarzott <zzam@gentoo.org>]

On Monday 30 August 2010, Pau Peris wrote:
> Hi, i would like to give persistent device names to the system hard
> drives (just renaming its original device name to the one i want using
> its serial number as identifier). I've created the following rules
> which are not currently working. I'm trying to use device serial
> numbers to properly set its device name. One of the main reasons for
> doing that is i have a RAID composed by 3 disk (let's say sda sdc sdd)
> and when i plug another 4 disks sda becomes sde, sdc becomes sdg and
> so on while new drives take old device names, that's why i would like
> to make it sure device names remains always the same.
> Here are the rules
> Código:
> 
> SUBSYSTEM=="block", ATTR{serial}="VNVB05G2RKTRZH", NAME="hda"
> SUBSYSTEM=="block", ATTR{serial}="9QK0T4WM", NAME="sda"
> SUBSYSTEM=="block", ATTR{serial}="3QD0X58D", NAME="sdb"
> SUBSYSTEM=="block", ATTR{serial}="9QK0RS9G", NAME="sdc"
> SUBSYSTEM=="block", ATTR{serial}="9VP0SBVN", NAME="sdc"
> 
> KERNEL=="hd*", SUBSYSTEM=="block", ATTR{serial}="VNVB05G2RKTRZH",
> NAME="hda%n" KERNEL=="sd*", SUBSYSTEM=="block", ATTR{serial}="9QK0T4WM",
> NAME="sda%n" KERNEL=="sd*", SUBSYSTEM=="block", ATTR{serial}="3QD0X58D",
> NAME="sdb%n" KERNEL=="sd*", SUBSYSTEM=="block", ATTR{serial}="9QK0RS9G",
> NAME="sdc%n" KERNEL=="sd*", SUBSYSTEM=="block", ATTR{serial}="9VP0SBVN",
> NAME="sdc%n"
> 
> 
> Should this work? Do some one know how can i get it to work? thanks in
> advanced

It could work if you fixed the rules as the other answers told you, but PLEASE 
don't do this!

There are a lot of arguments like dmesg output and sysfs content will no 
longer match userspace observations.
It will break once there is another disk that is not renamed and gets 
KERNEL=sda assigned.

Why do you not just use /dev/disk/by-* links as everyone else does?

Regard
Matthias