Linux – Permission denied as root

linuxpermissionsroot

The root user of Linux doesn't have permission to read/write a regular file, unless all users have permission to read/write this file, like below:

drwxrwsrwx ....... file_name

However the owner of the file can still read/write this file.

AND:

0) not the problem of execution, just read/write
1) not the problem of device because regular user can read/write it.
2) the result of command id:

uid=0(root) gid=0(root) groups=0(root)

so I don't think it's the problem of group.

So what other problems could be?

Best Answer

Check mounting options like 'rw' 'ro' (read, write issues), 'user' 'exec' (execution issues).

Related Solutions

Linux cp Permission denied on ntfs file system

It seems to me that permissions are not correctly set.

you are user g and can read a file = OK
but you can't create a file in a destination because the directory media is not writeable by you, only root can do that

So either copy as root or change the permissions on target so that you have a write permission on media directory.

As pointed out it's not possible to change permissions nor ownership on mounted NTFS filesystem. In that case there is a possibility to use proper mount options. Bellow excerpt from man mount

uid=value, gid=value and umask=value

Set the file permission on the filesystem. The umask value is given in octal. By default, the files are owned by root and not readable by somebody else.

Example: (for /dev/sdc1 with FAT32 filesystem)

Check that the device is not mounted (following should return without output)

$ mount | grep sdc1

Mount the device with uid and gid option set

$ sudo mount /dev/sdc1 -o uid=1000,gid=1000 /mnt

Verify the mountpoint

$ mount | grep sdc1

/dev/sdc1 on /mnt type vfat (rw,relatime,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)

Linux – Permission denied using Rsync as root

From the mainpage for rsyncd.conf:

auth users
       This parameter specifies a comma and space-separated list of usernames
       that will be allowed to connect to this module. The usernames do not need
       to exist on the local system. [...]

I.e., the usernames you choose for the rsync daemon are not linked to the system's users of the same name.

You can, however, set the user-ID and group-ID that the rsync daemon should use when accessing files (at least when you have started the daemon with root priviledges):

uid    This  parameter  specifies  the user name or user ID that file transfers to
       and from that module should take place as when the daemon was run as root.
       In combination with the "gid" parameter this determines what file permissions
       are available. The default is uid -2, which is normally the user "nobody".

gid    This parameter specifies the group name or group ID that file transfers to
       and from that module should take place as when the daemon  was  run  as  root.
       This complements the "uid" parameter. The default is gid -2, which is normally
       the group "nobody".

For example:

uid = johndoe
gid = johndoe

Best Answer

Related Solutions

Linux cp Permission denied on ntfs file system

Linux – Permission denied using Rsync as root

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