I have checked many similar questions but the solutions didn't work for me.On my previous Debian wheezy installation I could mount devices from GUI with no permission problem and also after upgrading to jessie. But on my new Debian jessie installation devices mount in a read-only state whether ntfs partitions on the same HDD as my Debian installation or external USB devices, for both root user and normal user, I can't write and modify data on mounted devices.I have found these lines in syslog that seems to be related.udisksd[1281]: Mounted /dev/sda4 at /media/jmuutt/<uuid> on behalf of uid 1000udisksd[1281]: Cleaning up mount point /media/jmuutt/<uuid> (device 8:4 is not mounted)udisksd[1281]: Unmounted /dev/sda4 on behalf of uid 1000kernel: [  125.190099] ntfs: volume version 3.1.udisksd[1281]: Mounted /dev/sda4 at /media/jmuutt/<uuid> on behalf of uid 1000org.gtk.Private.UDisks2VolumeMonitor[1224]: index_parse.c:191: indx_parse(): error opening /media/jmuutt/<uuid>/BDMV/index.bdmvorg.gtk.Private.UDisks2VolumeMonitor[1224]: index_parse.c:191: indx_parse(): error opening /media/jmuutt/<uuid>/BDMV/BACKUP/index.bdmvorg.gnome.Nautilus[1224]: Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.kernel: [  137.739543] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739579] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739655] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739678] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739702] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739767] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739791] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739814] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739894] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.kernel: [  137.739921] ntfs: (device sda4): ntfs_setattr(): Changes in user/group/mode are not supported yet, ignoring.I'm trying to figure out what makes the difference between two installations. In my new installation, unlike the previous one, I didn't install gnome task completely but only the minimal gnome packages. And the other difference is that the first time I created a fresh partition table and formatted all the partitions, ext4 and ntfs, then installed windows and then Debian, but second time I used the same partition table and only formatted ext4 partitions. Both times dual-boot with windows.The output of cat /etc/mtab for two internal and external mounted devices reads as follows:/dev/sdb1 /media/jmuutt/<uuid> ntfs rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0177,dmask=077,nls=utf8,errors=continue,mft_zone_multiplier=1 0 0/dev/sda4 /media/jmuutt/<uuid> ntfs rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0177,dmask=077,nls=utf8,errors=continue,mft_zone_multiplier=1 0 0
Permission denied on mounted devices
debian;permissions;mount;ntfs
After hours searching, there seems to be different causes for this issue and different solutions for each one.I'm not an expert to provide a comprehensive answer so I hint to some frequent situations on the topic:  Ownership/permission issues for mounted devices on mount points:File permissions won't changeUSB drive auto-mounted by user but gets write permissions for root onlyDamaged file-system that for security reasons mounts the device as read-only:Permission Denied on External Hard DriveHibernated windows that doesn't permit a write access to windows partitions on dual-boot systems:Unable to mount Windows (NTFS) filesystem due to hibernationAnd the one that led me to answer is the type of mounting based on the file-system:Why can't I write on External Hard disk?My problem was the missing NTFS driver package ntfs-3g that caused the system use the Linux kernel NTFS driver ntfs. As mentioned in Debian Wiki NTFS page, ntfs, Linux kernel NTFS driver, provides read-only access, and ntfs-3g, Userspace NTFS driver via FUSE, provides read and write access.# apt-get install ntfs-3g and a system reboot solved the problem for me.