I am telling ya all thing.
1.I installed Manjaro
2.I have 2 disk. A ssd a hdd. SSD and HDD is ext4.
3.I installed erase and install option with. Just SSD mounted as root.
4.HDD is mounted as just drive.
5.But I can not access. For example: I can not creating new file on it.
I tried this command:
sudo chown myusername /dev/sda1
lsblk ✔
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 465,8G 0 disk
└─sda1 8:1 0 465,8G 0 part /run/media/caner/db5e4d93-0478-4aab-b34e-cea7b62ff3e7
sdb 8:16 0 223,6G 0 disk
├─sdb1 8:17 0 300M 0 part /boot/efi
├─sdb2 8:18 0 214,5G 0 part /
└─sdb3 8:19 0 8,8G 0 part [SWAP]
/run is a temporary filesystem, it’s a place where software can put stuff without affecting the rest of the system. You should mount it elsewhere using fstab or systemd unit files.
I had a similar issue the other day, I have the KDE partition manager I created the partition using this. Don’t know if this will help you out, but worth a shot.