Fix filesystem errors with fsck
OCEAN IS IN BETA!
This guide applies to the Ocean BETA units that will ship in February 2016.
If you find a bug while using your Ocean and would like to report it, please send us an email about it!
This guide explains how to fix filesystem errors on your Ocean. File
You can only run fsck
on either unmounted, or readonly partition. When the Ocean is booted, we cannot unmount the OS partition. Instead, we will need to mount it in readonly mode, fix issues, and then restore the original settings.
Preparation
When mounting your partition in readonly mode, your WiFi chip will most likely not work. This guide is best followed steps using the USB console interface. If you have not already done so, please read the guide on how to use USB console interface before continuing.
Mounting disk as readonly
Start by finding the UUID
of your partition. This can be done by running blkid
, which should return something similar to:
$ blkid
/dev/mmcblk0: PTUUID="493c2a7b" PTTYPE="dos"
/dev/mmcblk0p1: SEC_TYPE="msdos" LABEL="boot" UUID="D331-6AEB" TYPE="vfat" PARTUUID="493c2a7b-01"
/dev/mmcblk0p2: LABEL="system" UUID="f8023c7c-8765-4780-ab74-0abccd0b3113" TYPE="ext4" PARTUUID="493c2a7b-02"
You are looking for the UUID of /dev/mmcblk0p2
partition. In the example above, my UUID is f8023c7c-8765-4780-ab74-0abccd0b3113
.
Next, edit /etc/fstab
with a text editor such as nano
or vim
. I suggest comment out anything that my be present. Copy and paste the following, replacing the UUID
with the UUID
of your partition:
UUID=f8023c7c-8765-4780-ab74-0abccd0b3113 / ext4 remount,ro 1 1
Reboot your Ocean to mount the partition as readonly. When you are in USB console mode, you can do this by pressing the home button.
Fixing partition and remounting drive
Once you have rebooted your Ocean, and you have logged back into the console, run fsck
:
$ fsck -y /dev/mmcblk0p2
Reboot once more (by pressing the home button again) and login again. Now make your root file system readble/writable:
$ mount -o remount,rw /dev/mmcblk0p2
Restore the default setting of /etc/fstab
(make sure you remove the reference to readonly mount), and reboot a final time (by, once again, pressing the home button). Congratulations, you've just rescued the file system on your Ocean!