ext4 only shows in /proc/mounts or moutinfo options that differ from default where default values are set in super block (during creation or by tune2fs). So presumably both options are already set as default. You can check full list of currently used mount options in /proc/fs/ext4/sda4/options
Ok, thats a good hint. So I set the journalmode to writeback tune2fs -o journal_data_writeback /dev/sda4 According to you there must be the "data=ordered been shown in the findmnt, cat /proc/mounts and mount. But: b-sekret:~ # findmnt /dev/sda4 TARGET SOURCE FSTYPE OPTIONS / /dev/sda4 ext4 ro,relatime As you can see, it is mounted readOnly. Nothing changed to fstab. The only thing I found in dmesg: EXT4-fs (sda4): Cannot change data mode on remount. It seems that the data-mode cannot be changes via fstab if it is the Root-Device. Regards Daniel -- Daniel Spannbauer Systemadministration marco Systemanalyse und Entwicklung GmbH Tel +49 8333 9233-27 Fax -11 Rechbergstr. 4-6, D 87727 Babenhausen Mobil +49 171 4033220 https://www.marco.de Email ds@marco.de Geschäftsführer Martin Reuter, Torsten Lukas HRB 171775 Amtsgericht München