I have an embedded system based on the RiotBoard, I have the main file system on the MMC set as read-only, and an 8gb usb flash drive for writeable storage. rootfs is debian, linux kernel version 4.3.0-rc2-00019-gbcee19f
Drive format commands are
mkfs.ext4 -U 2d4d3021-ebaf-4e29-b0e4-e8068d3bd237 /dev/sda1
tune2fs /dev/sda1 -i 0 //Don't check against time clock
tune2fs /dev/sda1 -c 1 //Check every time
and the FSTAB line
UUID=2d4d3021-ebaf-4e29-b0e4-e8068d3bd237 /mnt/USB1 ext4 data=journal,nofail 0 2
I keep getting this error
JBD2: Spotted dirty metadata buffer (dev = sda1, blocknr = 1087488). There's a risk of filesystem corruption in case of system crash.
with blocknr incrementing every time. This happens whether or not it is an unplanned power off, or reboot from the command line. I am a bit dubious that this drive has a real problem, it is a new sandisk brand drive.
Edit 1: Reformatting drive fixes this problem, so I am not clear why FSCKFIX=yes in /etc/default/rcS is not fixing this. The output of e2fsck was
Checking file systems...fsck from util-linux 2.20.1 e2fsck 1.42.5 (29-Jul-2012) /dev/sda1: recovering journal /dev/sda1 has been mounted 1 times without being checked, check forced. Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information Free blocks count wrong (1886088, counted=1886055). Fix? yes /dev/sda1: ***** FILE SYSTEM WAS MODIFIED ***** /dev/sda1: 57/488640 files (17.5% non-contiguous), 68117/1954172 blocks fsck died with exit status 1 ***skipped lines here*** JBD2: Spotted dirty metadata buffer (dev = sda1, blocknr = 1084928). There's a risk of filesystem corruption in case of system crash.