[SOLVED] several questions regarding ".rules" rule files and etc

andrewysk · 11-29-2020, 07:36 AM

I am learning how to change removable storage device to /media instead of KDE default /run/media/$USER.
As i am reading this url, i came across something that i don't understand.
Appreciate if someone can explain to me. TQ

ref:

Code:

https://wiki.archlinux.org/index.php/Udisks#Mount_to_.2Fmedia_.28udisks2.29

Code:

Mount to /media (udisks2)

By default, udisks2 mounts removable drives under the ACL controlled directory /run/media/$USER/. If you wish to mount to /media instead, use this rule:


	Code:
	/etc/udev/rules.d/99-udisks2.rules

# UDISKS_FILESYSTEM_SHARED
# ==1: mount filesystem to a shared directory (/media/VolumeName)
# ==0: mount filesystem to a private directory (/run/media/$USER/VolumeName)
# See udisks(8)
ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{UDISKS_FILESYSTEM_SHARED}="1"
Since /media, unlike /run, is not mounted by default as a tmpfs, you may also wish to create a tmpfiles.d snippet to clean stale mountpoints at every boot:

	Code:
	/etc/tmpfiles.d/media.conf

D /media 0755 root root 0 -

Q1.
Is it all rule files are located in the same folder location across all linux distro ? For example, i am using Arch based linux (endeavorous os to be exact).
Or it is has to do with KDE only ?
Let's say if i am using gnome of Endeavorous os.. will the rule files folder location still the same ?

Q2.
When i create such rule file as above, do i need to somehow "refresh" some module so that the system will make the "rule file" in effect ? Do i need to logout or reboot after the rule files is created, to take effect ?

Q3.
In above article, the rule file name is "/etc/udev/rules.d/99-disks2.rules", why "99-" ? I have came to understand that "99" is the priority over a rule file "98".. but since my folder has got no disks2.rules file, can i simply name it something like "09-disks2.rules" instead ? why "99-" was quoted as example ?

Q4.
What does snippet means ?

Q5.
Is this "etc/tmpfiles.d/media.conf" location and file is the place where snippet "settings" are store ? Can i put it that way; "settings"?
Likewise, just like the "/etc/udev/rules.d/99-disks2.rules" above, i can call this as "rules settings" of udev package ...

Q6.
Please explain what does this mean.

Code:

/etc/tmpfiles.d/media.conf

D /media 0755 root root 0 -

I asked such funny questions because i am so very confused with linux way of how things work!
Thanks

berndbausch · 11-29-2020, 08:32 AM

I can answer some questions and point you to answers of others.

Quote:

Originally Posted by andrewysk

Q1.
Is it all rule files are located in the same folder location across all linux distro ? For example, i am using Arch based linux (endeavorous os to be exact).
Or it is has to do with KDE only ?
Let's say if i am using gnome of Endeavorous os.. will the rule files folder location still the same ?

Yes, most likely the same locations across all or most Linux distros. It has nothing to do with KDE or Gnome.

Quote:

Q2.
When i create such rule file as above, do i need to somehow "refresh" some module so that the system will make the "rule file" in effect ? Do i need to logout or reboot after the rule files is created, to take effect ?

I think that you need to tell udevd to reload the rules. For example udevadm control -R perhaps followed by udevadm trigger, or systemctl reload udevd, or systemctl restart udevd.

Quote:

Q3.
In above article, the rule file name is "/etc/udev/rules.d/99-disks2.rules", why "99-" ? I have came to understand that "99" is the priority over a rule file "98".. but since my folder has got no disks2.rules file, can i simply name it something like "09-disks2.rules" instead ? why "99-" was quoted as example ?

The 99 ensures that it is the last rule that is processed. You may get into trouble if you change the number, either now or when other rules are added.

Quote:

Q4.
What does snippet means ?

You mean this?

Code:

ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{UDISKS_FILESYSTEM_SHARED}="1"

It sets an environment variable named UDISKS_FILESYSTEM_SHARED. Its meaning is explained in the udisks manual page.

Quote:

Q5.
Is this "etc/tmpfiles.d/media.conf" location and file is the place where snippet "settings" are store ? Can i put it that way; "settings"?

Sorry, I don't understand your question. tmpfiles.d contains rules for handling temporary files when the system stops. Check the manual page for tmpfiles.d for details.

Quote:

Likewise, just like the "/etc/udev/rules.d/99-disks2.rules" above, i can call this as "rules settings" of udev package ...

tmpfiles.d is not directly related to udevd.

Quote:

Q6.
Please explain what does this mean.

Code:

/etc/tmpfiles.d/media.conf

D /media 0755 root root 0 -

Use the abovementioned manual page.