[solved] ext4 removable media usable by anyone on any computer.

talnotag · 2010-07-27 18:35:52

Hi there !

Is there something special to know about ext4 and extern USB hard drive ? I used Gnome DIsk Utility to format it, and when i plug it, it mounts ok but with root, so I can't write data on it. Is there a way to fix it please ?

Last edited by talnotag (2010-07-28 01:10:45)

karol · 2010-07-27 18:45:46

How exactly do you mount it: udev, pmount?

talnotag · 2010-07-27 18:48:05

udev I assume since it's automount. Anyway I don't remember I configured anything about that at installation...

karol · 2010-07-27 18:51:28

http://wiki.archlinux.org/index.php/Ude … n-mounting

Gusar · 2010-07-27 19:41:52

"Gnome Disk Utility" means udisks. Which means policykit. Ugh.

Actually, I have an idea: Mount the disk. Now, the directory it's mounted at (it'll most likely be /media/label_of_disk), change it's permissions - as root do:

chown talnotag:talnotag /media/label_of_disk

Now you should in theory be able to write data on the disk.

karol · 2010-07-27 19:44:56

@ Gusar
'chown -R' maybe? Just in case there's already something there.

talnotag · 2010-07-27 23:01:58

Thanks for your answers. Maybe I should format it again using another tool then ?

Last edited by talnotag (2010-07-27 23:02:16)

karol · 2010-07-27 23:03:15

talnotag wrote:

Thanks for your answers. Maybe I should format it again using another tool then ?

So the chown didn't work? That would be really weird.

talnotag · 2010-07-27 23:10:38

karol wrote:

talnotag wrote:
Thanks for your answers. Maybe I should format it again using another tool then ?
So the chown didn't work? That would be really weird.

It worked, just wondering if the problem would occur again after next reboot, or if it fixed for any computer i would plug this HD in ?

(sorry for my approximative english)

karol · 2010-07-27 23:35:18

> if it fixed for any computer i would plug this HD in ?
If you have the same user everywhere it should work.

fsckd · 2010-07-27 23:40:02

Same UID that is.

karol · 2010-07-27 23:44:05

fsckd wrote:

Same UID that is.

That's what I meant. I've heard that they may differ from one distro to another, but if all the boxes are running Arch, will that be a problem?

fsckd · 2010-07-27 23:59:13

Depends on how these boxes of Arch are configured.

karol · 2010-07-28 00:11:26

fsckd wrote:

Depends on how these boxes of Arch are configured.

Default. Root + one user. Will the user get the same UID (1000) on every box?

fsckd · 2010-07-28 00:14:49

Depends on the guy who installs it.

I can go on all day.

talnotag · 2010-07-28 00:41:52

Ok, let's say I have to format it again ^^

Thanks everyone.

fsckd · 2010-07-28 00:43:00

No you don't. Worst case you have to chown -R again.

talnotag · 2010-07-28 00:45:56

I'd like to be able to easily use it on any linux box I find with any user, just like a normal external HD : plug and read/write. This UID protection thing is anoying in my case.

karol · 2010-07-28 00:48:36

talnotag wrote:

I'd like to be able to easily use it on any linux box I find with any user, just like a normal external HD : plug and read/write. This UID protection thing is anoying in my case.

You won't escape from UID on a Linux filesystem, but if you can use vfat you won't have such 'problems', just mount your drive as a user.

talnotag · 2010-07-28 00:52:32

So the only filesystem that can handle 4Go+ files and is easy to use with removable media is NTFS ? No way to format it using ext3 or 4 and use it as a normal USB disk ?

karol · 2010-07-28 00:57:26

If you give everyone every permission you will be able to do whatever you want.

[karol@black ~]$ touch abc
[karol@black ~]$ ls -al abc 
-rw-r--r-- 1 karol users 0 07-28 03:05 abc
[karol@black ~]$ chmod 777 abc 
[karol@black ~]$ ls -al abc 
-rwxrwxrwx 1 karol users 0 07-28 03:05 abc

talnotag · 2010-07-28 01:00:49

I was thinking about that at the same moment, but will it bo ok for new files added in the future as well ?

karol · 2010-07-28 01:04:29

talnotag wrote:

I was thinking about that at the same moment, but will it bo ok for new files added in the future as well ?

https://bbs.archlinux.org/viewtopic.php … 81#p799381
In theory you could create all files with 777 permissions and mount the drive accordingly http://en.wikipedia.org/wiki/Umask

talnotag · 2010-07-28 01:09:15

karol wrote:

talnotag wrote:
I was thinking about that at the same moment, but will it bo ok for new files added in the future as well ?
https://bbs.archlinux.org/viewtopic.php … 81#p799381
In theory you could create all files with 777 permissions and mount the drive accordingly http://en.wikipedia.org/wiki/Umask

Ok sounds good, I think it will be ok.
Thanks a lot for your help ! I hope there will be a real free filesystem made for large removable device one day.

fsckd · 2010-07-28 01:10:30

Edit: Sorry, I thought you were refusing to answer my question as it was a bit too personal.

Here it is again as far as I remember it: If I may ask, where do you plan on mounting this device, at a friends' box, at your workplace, across the nation in a mount-on-every-Linux-box-you-find trip?

Last edited by fsckd (2010-07-28 01:52:42)

Arch Linux

#1 2010-07-27 18:35:52

[solved] ext4 removable media usable by anyone on any computer.

#2 2010-07-27 18:45:46

Re: [solved] ext4 removable media usable by anyone on any computer.

#3 2010-07-27 18:48:05

Re: [solved] ext4 removable media usable by anyone on any computer.

#4 2010-07-27 18:51:28

Re: [solved] ext4 removable media usable by anyone on any computer.

#5 2010-07-27 19:41:52

Re: [solved] ext4 removable media usable by anyone on any computer.

#6 2010-07-27 19:44:56

Re: [solved] ext4 removable media usable by anyone on any computer.

#7 2010-07-27 23:01:58

Re: [solved] ext4 removable media usable by anyone on any computer.

#8 2010-07-27 23:03:15

Re: [solved] ext4 removable media usable by anyone on any computer.

#9 2010-07-27 23:10:38

Re: [solved] ext4 removable media usable by anyone on any computer.

#10 2010-07-27 23:35:18

Re: [solved] ext4 removable media usable by anyone on any computer.

#11 2010-07-27 23:40:02

Re: [solved] ext4 removable media usable by anyone on any computer.

#12 2010-07-27 23:44:05

Re: [solved] ext4 removable media usable by anyone on any computer.

#13 2010-07-27 23:59:13

Re: [solved] ext4 removable media usable by anyone on any computer.

#14 2010-07-28 00:11:26

Re: [solved] ext4 removable media usable by anyone on any computer.

#15 2010-07-28 00:14:49

Re: [solved] ext4 removable media usable by anyone on any computer.

#16 2010-07-28 00:41:52

Re: [solved] ext4 removable media usable by anyone on any computer.

#17 2010-07-28 00:43:00

Re: [solved] ext4 removable media usable by anyone on any computer.

#18 2010-07-28 00:45:56

Re: [solved] ext4 removable media usable by anyone on any computer.

#19 2010-07-28 00:48:36

Re: [solved] ext4 removable media usable by anyone on any computer.

#20 2010-07-28 00:52:32

Re: [solved] ext4 removable media usable by anyone on any computer.

#21 2010-07-28 00:57:26

Re: [solved] ext4 removable media usable by anyone on any computer.

#22 2010-07-28 01:00:49

Re: [solved] ext4 removable media usable by anyone on any computer.

#23 2010-07-28 01:04:29

Re: [solved] ext4 removable media usable by anyone on any computer.

#24 2010-07-28 01:09:15

Re: [solved] ext4 removable media usable by anyone on any computer.

#25 2010-07-28 01:10:30

Re: [solved] ext4 removable media usable by anyone on any computer.

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