How Do You Troubleshoot a quotacheck Command Failure with “Cannot guess format from filename…Please specify format on commandline”?

One of the following apply to your situation:

Problem scenario #1
You are running a quotacheck command. You get this error:

quotacheck: Cannot guess format from filename on /dev/mapper/ubuntu--vg-ubuntu--lv. Please specify format on commandline.
quotacheck: Cannot find filesystem to check or filesystem not mounted with quota option.

What should you do?

or
Problem scenario #2
You try to run an edquota command, but you get "Cannot find any quota file to work on. No file systems with quota detected." What should you do?

or

Problem scenario #3
You get an error like this:

quotacheck: Cannot guess format from filename on foobar. Please specify format on commandline.
quotacheck: Cannot find filesystem to check or filesystem not mounted with quota option.

What should you do?

Possible Solution #1 (for a Red Hat distribution of Linux)

1. Remove the aquota.group and aquota.user files
2. Run this (but change "vfsv1" to "vfsv0" if you are using a 32 bit OS):

sudo quotacheck -F vfsv1 -avum

This solution was adapted from https://talk.plesk.com/threads/hard-diskquota-install-error.258095/

Possible Solution #2 (for a non Red Hat distribution of Linux)
According to Red Hat documentation, this probably would not help a Red Hat derivative Linux system. Below could help a non-Red Hat Linux system.

Backup the /etc/fstab file to (.bak in some accessible directory). Keep the original backup in case there is a problem.

Update the /etc/fstab file.

Is the word "quota" near the "grpquota" word on the line for the file system you want to have a quota enforced?

Here is a version of an incorrect /etc/fstab file that will cause the problem:

/dev/disk/by-id/dm-uuid-LVM-abcd1234 / ext4 defaults,grpquota 0 0
# /boot was on /dev/sda2 during curtin installation
/dev/disk/by-uuid/987654321 /boot ext4 defaults 0 0

Here is a correct version of /etc/fstab:

/dev/disk/by-id/dm-uuid-LVM-abcd1234 / ext4 defaults,quota,grpquota 0 0
# /boot was on /dev/sda2 during curtin installation
/dev/disk/by-uuid/987654321 /boot ext4 defaults 0 0

Remount the relevant mount point (with a sudo mount -o remount /relevant/mount/point) or reboot after your /etc/fstab has been corrected.

Possible Solution #3
See these postings:

https://www.howtoforge.com/community/threads/quotacheck-cannot-find-filesystem-to-check.25954/
https://blog.naver.com/syseoz/220458453446