When working remotely, I set a server to force an fsck at boot time with the command:
sudo touch /forcefsck
and rebooted.
After it restarted, I checked in /var/log/fsck for the results of the disk check.
Both checkfs and checkroot said:
Nothing has been logged yet
So where are the results saved?
For Ubuntu 16.04 and 18.04 root partitions
You're likely looking for /run/initramfs/fsck.log.
An fsck of the root filesystem necessarily happens before the root filesystem has been mounted as writable, so the filesystem check occurs early in the boot process while the system is still running from the initramfs. An fsck log is written to a RAM-backed filesystem (tmpfs) that is available for writing at this time, and it continues to be available after boot at /run/initramfs/fsck.log. This is volatile storage, so fsck logs are lost once the system reboots. It would be nice if these logs were copied to non-volatile storage after the root filesystem is mounted as writable, but this does not appear to be the case.
Here's an example:
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 238.5G 0 disk
├─sda1 8:1 0 512M 0 part /boot/efi
└─sda2 8:2 0 238G 0 part /
$ cat /run/initramfs/fsck.log
Log of fsck -C -a -V -t ext4 /dev/sda2
Fri Nov 30 22:35:21 2018
fsck from util-linux 2.31.1
[/sbin/fsck.ext4 (1) -- /dev/sda2] fsck.ext4 -a -C0 /dev/sda2
/dev/sda2: clean, 653295/15597568 files, 6658147/62383360 blocks
Fri Nov 30 22:35:21 2018
----------------
Possibly you are affected by this bug: "Does not log fsck invocations in /var/log/fsck/".
Doug's comment on the bug suggests the following workaround (the formatting has been adjusted to this platform):
12.04 Force FIlesystem Check:
Tell system to force filesystem checks on startup for all filesystems in
/etc/fstabwith indications to do filesystem checks:touch /forcefsckTell system to be more verbose at startup:
sudo sed -i "s/VERBOSE=no/VERBOSE=yes/" /etc/default/rcSThen, after reboot, examine
/var/log/boot.log, the results of the filesystem check will be visible there.If you also want the filesystem check to perform all repairs, make this change:
sudo sed -i "s/FSCKFIX=no/FSCKFIX=yes/" /etc/default/rcS14.04 Force FIlesystem Check:
Tell system to force filesystem checks on startup for all filesystems in
/etc/fstabwith indications to do filesystem checks:touch /forcefsckTell system to be more verbose at startup:
sudo sed -i "s/#VERBOSE=no/VERBOSE=yes/" /etc/default/rcSThen, after reboot, examine
/var/log/upstart/mountall.log, the results of the filesystem check will be visible there.If you also want the filesystem check to perform all repairs, make this change:
sudo sed -i "s/#FSCKFIX=no/FSCKFIX=yes/" /etc/default/rcS
I found some fsck logs in /var/log/upstart/mountall.log.
For Ubuntu 16.04
The command
journalctl -b --no-pager | grep systemd-fsck
reports non root partition file system checks.similar to this:
Mar 22 15:06:26 64bitUbuntu systemd-fsck[750]: /dev/sdb1: clean, 146223/121454592 files, 356711795/485818368 blocks
For root partition checks at boot issue the command
more /var/log/boot.log
Provides results similar to this:
/dev/sda2: clean, 349091/1954064 files, 2379983/7814912 blocks
For Ubuntu 18.04
The command journalctl -b --no-pager | grep systemd-fsck and grep systemd-fsck /var/log/syslog
both report non root partition file system checks.similar to this:
Sep 25 16:06:29 me-Z370-HD3P systemd-fsck[615]: Scratch: clean, 19/6520832 files, 555602/26081280 blocks
Sep 25 16:06:29 me-Z370-HD3P systemd-fsck[609]: /dev/sda1: clean, 47014/89374720 files, 294970235/357492992 blocks
Sep 25 16:06:29 me-Z370-HD3P systemd-fsck[613]: /dev/sda5: clean, 6707/32727040 files, 7464312/130885120 blocks
Checks of root partitions mounted by UUID results don't appear to be logged even if forced.
Testing this with Ubuntu 12.04.5 LTS and I found the log on /var/log/boot.log
└❯ grep -A 1 fsck /var/log/*
/var/log/boot.log:fsck from util-linux 2.20.1
/var/log/boot.log-/dev/vda1: 209262/2621440 files (0.1% non-contiguous), 3239494/10485504 blocks
