apt install quotas
find /lib/modules/`uname -r` -type f -name '*quota_v*.ko*'

# In /etc/fstab:
s/errors=remount-ro/usrquota,grpquota/
s/1$/0/

quotacheck -cugm /
quotaon -ugv /
quotaoff -ugv /
setquota -u user block-soft block-hard inode-soft inode-hard /
# list all quotas
repquota -a