Question about chown

rado84

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I finally found out how to have an ext4 FS automatically mounted at startup, so now I'm gonna migrate almost all of my storages to ext4. One thing troubles me though - setting user rights with chown: when you set rights with chown, do they remain forever? Or do I have to set them up again, IF one day I have to reinstall Arch for whatever reason?
 


gvisoc

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They are kept forever as they are part of the file system.

As far as I understand, what you need to care about when you reinstall your system are the group and user ID of the owners, for them to match.

I presume that such situation might have been experienced by someone else in the forum, and it’s the same that happens when you have your /home in another partition and reinstall the OS in /.

My upfront idea to test would be focus on single-user groups I’d create, and for which I can control the GID, rather than on users and groups that are default for the system, present in a lot of files, and that may change at the distribution’s will, or that may be different from one distribution to another.
 

gvisoc

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And now that I think of it, you may be able to translate UID and GID it my means of fstab / mount, anyway.
 

f33dm3bits

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And now that I think of it, you may be able to solve it my means of fstab / mount, anyway.
Yeah you can just set your ext4 filesystems up in fstab, once the ownership and permissions are set once they will remain.
 
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rado84

rado84

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And now that I think of it, you may be able to translate UID and GID it my means of fstab / mount, anyway.
I was told I didn't need to add uid and gid to the string in fstab for an ext4 since that's set with chown.

As for the concerns about home and groups, that's not a concern to me bc I always install home on the same partition where Linux is and the group always has the same name as my user. I don't like it the other way where home is on a different partition.
 

KGIII

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If I am understanding your concerns correctly...

The chown permissions remain - and so long as your UID is 1001 (or is it 1000?, whatever the default is) you won't actually have to mess with it again - even after re-installing - as the default user will have the default UID.

Now, if you make another user besides the default user, they'll need permission to access the disks.

I have chowned disks that have gone through all sorts of installs and never need to be adjusted.
 

gvisoc

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That’s great to know, I wasn’t certain that the defaults for the first user were 1000 (or 1001). Thanks!
 

wizardfromoz

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1000 is provided at installation time.

Wiz
 

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rado84

rado84

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1000 is provided at installation time.

Wiz
If my reasoning is correct, that would explain why I didn't have to set uid or gid in fstab for ext4. When the partitions were NTFS I had to state both uid and gid in fstab but now I'm thinking these were unnecessary because of my reasoning below.

1000 is root and when I installed Arch I gave my user (rado) administrative rights during the installation itself. Then, through the GUI I set up a group with the same name and set it to have the same rights as the root group. So without knowing (back when I installed Arch) I've set my user to uid and gid 1000. :)
 

wizardfromoz

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Slight correction.

Significant, I would say. Root's UID and GID is zero, and that is why it is so powerful.

My output for David G.'s command is

Code:
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
adm:x:3:4:adm:/var/adm:/sbin/nologin
lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
sync:x:5:0:sync:/sbin:/bin/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin
nobody:x:65534:65534:Kernel Overflow User:/:/sbin/nologin
dbus:x:81:81:System message bus:/:/sbin/nologin
unbound:x:999:999:Unbound DNS resolver:/etc/unbound:/sbin/nologin
tss:x:59:59:Account used for TPM access:/dev/null:/sbin/nologin
geoclue:x:998:998:User for geoclue:/var/lib/geoclue:/sbin/nologin
rtkit:x:172:172:RealtimeKit:/proc:/sbin/nologin
polkitd:x:997:997:User for polkitd:/:/sbin/nologin
pipewire:x:996:996:PipeWire System Daemon:/var/run/pipewire:/sbin/nologin
systemd-network:x:192:192:systemd Network Management:/:/usr/sbin/nologin
systemd-oom:x:995:995:systemd Userspace OOM Killer:/:/usr/sbin/nologin
systemd-resolve:x:193:193:systemd Resolver:/:/usr/sbin/nologin
systemd-timesync:x:994:994:systemd Time Synchronization:/:/usr/sbin/nologin
systemd-coredump:x:993:993:systemd Core Dumper:/:/usr/sbin/nologin
flatpak:x:992:992:User for flatpak system helper:/:/sbin/nologin
avahi:x:70:70:Avahi mDNS/DNS-SD Stack:/var/run/avahi-daemon:/sbin/nologin
sstpc:x:991:989:Secure Socket Tunneling Protocol(SSTP) Client:/var/run/sstpc:/sbin/nologin
chrony:x:990:988::/var/lib/chrony:/sbin/nologin
rpc:x:32:32:Rpcbind Daemon:/var/lib/rpcbind:/sbin/nologin
usbmuxd:x:113:113:usbmuxd user:/:/sbin/nologin
openvpn:x:989:987:OpenVPN:/etc/openvpn:/sbin/nologin
colord:x:988:986:User for colord:/var/lib/colord:/sbin/nologin
abrt:x:173:173::/etc/abrt:/sbin/nologin
setroubleshoot:x:987:985::/var/lib/setroubleshoot:/sbin/nologin
nm-openvpn:x:986:984:Default user for running openvpn spawned by NetworkManager:/:/sbin/nologin
openvswitch:x:985:983:Open vSwitch Daemons:/:/sbin/nologin
nm-openconnect:x:984:980:NetworkManager user for OpenConnect:/:/sbin/nologin
lightdm:x:983:979::/var/lib/lightdm:/sbin/nologin
rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin
vboxadd:x:982:1::/var/run/vboxadd:/sbin/nologin
sshd:x:74:74:Privilege-separated SSH:/usr/share/empty.sshd:/sbin/nologin
dnsmasq:x:981:977:Dnsmasq DHCP and DNS server:/var/lib/dnsmasq:/sbin/nologin
tcpdump:x:72:72::/:/sbin/nologin
chris:x:1000:1000:chris:/home/chris:/bin/bash

So root at top, and chris at bottom.

Each output line consists of seven (7) fields, which can sometimes include an empty field looking like this.

::

Redhat have an article here which explains

https://www.redhat.com/sysadmin/user-account-gid-uid

Avagudweegend, off to look for music for Rock Roxx ;)

Chris
 
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