Freebsd – Force fsck at boot time on the root file system (prior to mounting file systems, without Single-User mode)

freebsdfsck

How to automatically force fsck disks after crash in `systemd`? – does not mean anything.

Setting fsck_y_enable="YES" and background_fsck="NO" in /etc/rc.conf don't do anything.

My root file system is not clean and has a lot of errors (due to a power outage – unexpected shutdown, not because hard drive or hardware are bad).

fsck shows errors:

root@host2:/usr/home/alex # fsck
** /dev/mirror/gm0p2 (NO WRITE)
** Last Mounted on /
** Root file system
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
UNREF FILE I=8268305  OWNER=root MODE=140777
SIZE=0 MTIME=Jun  6 21:58 2014
CLEAR? no

[skipped 100+ lines]

I don't have physical or KVM access to the server.
This is gmirrored drive

FreeBSD host2.domain.tld 9.2-RELEASE FreeBSD 9.2-RELEASE #0 r255898: Thu Sep 26 22:50:31 UTC 2013 root@bake.isc.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64

# Device                Mountpoint      FStype  Options Dump    Pass#
/dev/mirror/gm0p2       /               ufs     rw      1       1
/dev/mirror/gm0p3       none            swap    sw      0       0

Best Answer

FreeBSD has properly working forced unmount, so you don't really need to do this at boot. Just log in (remotely), remount rootfs as read-only (mount -fur /), do fsck manually (fsck -y /) and then reboot the machine.

`ext4` filesystem check during boot

Tested on OS: Linux Mint 18.x in a Virtual Machine

Basic information

/etc/fstab has the fsck order as the last (6th) column, for instance:

<file system>    <mount point>    <type>    <options>    <dump>    <fsck>
UUID=2fbcf5e7-1234-abcd-88e8-a72d15580c99 / ext4 errors=remount-ro 0 1

FSCKFIX=yes variable in /etc/default/rcS

This will change the fsck to auto fix, but not force a fsck check.

From man rcS:

FSCKFIX
    When  the  root  and all other file systems are checked, fsck is
    invoked with the -a option which means "autorepair".   If  there
    are  major  inconsistencies then the fsck process will bail out.
    The system will print a  message  asking  the  administrator  to
    repair  the  file  system manually and will present a root shell
    prompt (actually a sulogin prompt) on the console.  Setting this
    option  to  yes  causes  the fsck commands to be run with the -y
    option instead of the -a option.  This will tell fsck always  to
    repair the file systems without asking for permission.

From man tune2fs

If you are using journaling on your filesystem, your filesystem
will never be marked dirty, so it will not normally be checked.

Start with

Setting the following

FSCKFIX=yes

in the file

/etc/default/rcS

Check and note last time fs was checked:

sudo tune2fs -l /dev/sda1 | grep "Last checked"

These two options did NOT work

Passing -F (force fsck on reboot) argument to shutdown:
```
shutdown -rF now
```
Nope; see: man shutdown.

Adding the /forcefsck empty file with:

touch /forcefsck

These scripts seem to use this:

/etc/init.d/checkfs.sh
/etc/init.d/checkroot.sh

did NOT work on reboot, but the file was deleted.

Verified by:

sudo tune2fs -l /dev/sda1 | grep "Last checked"
sudo less /var/log/fsck/checkfs
sudo less /var/log/fsck/checkroot

These seem to be the logs for the init scripts.

I repeat, these two options did NOT work!

Both of these methods DID work

systemd-fsck kernel boot switches

Editing the main grub configuration file:
```
sudoedit /etc/default/grub
```
```
GRUB_CMDLINE_LINUX="fsck.mode=force"
```
```
sudo update-grub
sudo reboot
```
This did do a file system check as verified with:
```
sudo tune2fs -l /dev/sda1 | grep "Last checked"
```
Note: This DID a check, but to force a fix too, you need to specify fsck.repair="preen", or fsck.repair="yes".
Using tune2fs to set the number of file system mounts before doing a fsck, man tune2fs
```
tune2fs' info is kept in the file system superblock
```
-c switch sets the number of times to mount the fs before checking the fs.
```
sudo tune2fs -c 1 /dev/sda1
```
Verify with:
```
sudo tune2fs -l /dev/sda1
```
This DID work as verified with:
```
sudo tune2fs -l /dev/sda1 | grep "Last checked"
```

Summary

To force a fsck on every boot on Linux Mint 18.x, use either tune2fs, or fsck.mode=force, with optional fsck.repair=preen / fsck.repair=yes, the kernel command line switches.

Best Answer

Related Solutions

Linux Ext4 – Force Root Filesystem Check at Boot

ext4 filesystem check during boot