CentOS - Feb 2019 - What files to edit when changing the sdX of hard drives?

Hi

I have read instructions for udev, I also found many example on how to do this.
I want to lock in the SDA/SDB/SDC for my drives and I came up with a rule like
this

  KERNEL=="sd?", SUBSYSTEM=="block",
ENV{ID_SERIAL}=="ST500DM002-1BC142_W2A56H8A", NAME="sda",
RUN+="/usr/bin/logger ID_SERIAL=$ENV{ID_SERIAL} set to /dev/sda ",
GOTO="END_PERSISTENT_DISK"

However, it is not clear to me is in what files I need to add my rules.


Do I add a random file "99-my-rules.rules" in
"/etc/udev/rules.d/"?

Do I copy a file from "/usr/lib/udev" to
"/etc/udev/rules.d/" and add my rules?

Do I need to be careful with the NUMBER, e.g. "60-my-rule.rules"?


Jobst




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Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit?:
> I want to lock in the SDA/SDB/SDC for my drives
In short : use UUIDs or labels instead of hardcoding /dev/sdX.

https://wiki.archlinux.org/index.php/persistent_block_device_naming

Cheers,

Niki

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Nicolas Kovacs wrote:
> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit?:
>
>> I want to lock in the SDA/SDB/SDC for my drives
>
> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
>
> https://wiki.archlinux.org/index.php/persistent_block_device_naming
Yeah - I strongly believe in labels, given the fact that *no* one can
remember a UUID....

      mark

On Thu, Feb 28, 2019 at 05:19:49PM +0100, Nicolas Kovacs (info at microlinux.fr)
wrote:
> Le 28/02/2019 ? 04:12, Jobst Schmalenbach a ?crit?:
> > I want to lock in the SDA/SDB/SDC for my drives
> 
> In short : use UUIDs or labels instead of hardcoding /dev/sdX.
I **KNOW** how to use UUID's ... this is NOT the reason why I am doing this!


I *NEED* the order of the disks to be SDA(1st BIOS drive) SDB(2nd BIOS drive)
SDC(3rd BIOS drive) and not SDA (1st BIOS drive) SDB(3rd BIOS drive) SDC (2nd
BIOS drive).

Reason: it stuffs up the use of grub2* utilities leaving behind a bunch of error
messages.
The SDA (1st BIOS drive) and SDB (2nd BIOS drive) are part of a MDADM raid(1)
system.

As soon as I plug in the third drive, the OS (or systemD) decides to put it into
the SDB spot - I do NOT want that.
When I the use any of the grub2 utils I end up with "missing drive"
errors.

If I leave the drive out NO problem. I have managed twice to have the machine
booting with the third drive as SDC, when that happens I I do not get any error
messages.



Jobst


-- 
Why is the man who invests all your money called a broker?

  | |0| |   Jobst Schmalenbach, General Manager
  | | |0|   Barrett & Sales Essentials
  |0|0|0|   +61 3 9533 0000, POBox 277, Caulfield South, 3162, Australia