如何在 Linux / Unix 中使用 df 命令（附示例）

Filesystem       1K-blocks     Used      Avail Capacity  Mounted on
zroot/rsnapshot 3133726266 83069592 3050656673     3%    /rsnapshot

Filesystem                  Size    Used   Avail Capacity  Mounted on
zroot/ROOT/default          3.3T    129G    3.1T     4%    /
devfs                       1.0k    1.0k      0B   100%    /dev
zroot/tmp                   3.1T    164k    3.1T     0%    /tmp
zroot                       3.1T    131k    3.1T     0%    /zroot
zroot/rsnapshot             3.2T     85G    3.1T     3%    /rsnapshot
zroot/backuplxdimages       3.5T    350G    3.1T    10%    /backuplxdimages
zroot/jails                 3.1T    131k    3.1T     0%    /jails
zroot/usr/home              3.2T     33G    3.1T     1%    /usr/home
zroot/var/crash             3.1T    638M    3.1T     0%    /var/crash
zroot/var/mail              3.1T    257k    3.1T     0%    /var/mail
zroot/var/audit             3.1T    131k    3.1T     0%    /var/audit
zroot/var/log               3.1T    2.6M    3.1T     0%    /var/log
zroot/usr/ports             3.1T    1.0G    3.1T     0%    /usr/ports
zroot/var/tmp               3.1T    131k    3.1T     0%    /var/tmp
zroot/usr/src               3.1T    131k    3.1T     0%    /usr/src
zroot/jails/dnscrypt        3.1T    887M    3.1T     0%    /jails/dnscrypt
zroot/jails/fullbasejail    3.1T    692M    3.1T     0%    /jails/fullbasejail
devfs                       1.0k    1.0k      0B   100%    /jails/dnscrypt/dev

Filesystem     Type  Size  Used Avail Use% Mounted on
/dev/md0       ext4  3.9G  350M  3.4G  10% /boot

Filesystem             Type    Size    Used   Avail Capacity  Mounted on
zroot/backuplxdimages  zfs     3.5T    350G    3.1T    10%    /backuplxdimage

Filesystem     Type     Inodes IUsed IFree IUse% Mounted on
udev           devtmpfs   2.1M   317  2.1M    1% /dev
tmpfs          tmpfs      2.1M   556  2.1M    1% /run
/dev/xvda1     ext4        41M  105k   41M    1% /
tmpfs          tmpfs      2.1M     1  2.1M    1% /dev/shm
tmpfs          tmpfs      2.1M     3  2.1M    1% /run/lock
tmpfs          tmpfs      2.1M    18  2.1M    1% /sys/fs/cgroup
/dev/loop0     squashfs     17    17     0  100% /snap/amazon-ssm-agent/2996
/dev/loop1     squashfs     16    16     0  100% /snap/amazon-ssm-agent/3552
/dev/loop3     squashfs    13k   13k     0  100% /snap/core/10958
/dev/loop4     squashfs    11k   11k     0  100% /snap/core18/1988
/dev/loop5     squashfs    11k   11k     0  100% /snap/core18/1997
/dev/loop6     squashfs   1.6k  1.6k     0  100% /snap/lxd/20371
tmpfs          tmpfs      2.1M     3  2.1M    1% /var/snap/lxd/common/ns
/dev/loop8     squashfs    13k   13k     0  100% /snap/core/11081
/dev/loop2     squashfs   1.6k  1.6k     0  100% /snap/lxd/20400
tmpfs          tmpfs      2.1M    22  2.1M    1% /run/user/1000

Filesystem                Type  Size  Used Avail Use% Mounted on
/dev/mapper/vgubuntu-root ext4  915G  165G  705G  19% /
/dev/nvme0n1p2            ext4  1.4G  392M  925M  30% /boot
/dev/nvme0n1p1            vfat  511M   30M  482M   6% /boot/efi
total                     -     917G  165G  706G  19% -

#!/bin/bash
# Name: disk-monitor-script.sh
# Usage: Poor mans disk space monitoring script to alert sysadmin/developer before running
#        out of disk/partition space.
# Author: Vivek Gite under GPLv 2.x+
#
# Warning: *** DO NOT USE THIS SCRIPT BLINDLY. *** 
#          *** This script mostly fails in your environment if requirements are not met. *** 
#
# Prerequisite (or as per your set up): 
#    You must have working SMTPD/email routing in place and subscription to pushover
#    notifications service for Android, iPhone, iPad, etc all:
#    a) Pushover - https://www.example.com/mobile-devices/android/how-to-push-send-message-to-ios-and-android-from-linux-cli/
#    b) AWS SES - https://www.example.com/faq/how-to-send-emails-with-postfix-and-amazon-aws-ses-on-rhel-centos-8/
# 
# Tested on - RHEL 7.x/8.x and Debian/Ubuntu LTS versions 
# 
# Last revised - 12/Jan/2017 by Vivek Gite, added $DC_P
# -----------------------------------------------------------------------------------------
DC_P="AWS" # either AWS or Linode 
ADMIN="foo@somewhere-tld"
FROM="system-user-ec2@my-corp-tld"
SUBJECT="Alert out of disk space - $HOSTNAME [${DC_P}]"
 
# Set alert level 90% is default
ALERT=90
 
# See https://www.example.com/mobile-devices/android/how-to-push-send-message-to-ios-and-android-from-linux-cli/
source /home/scripts/cli_app.sh
 
# Send html email and push notification to my iPhone/Android device
df -H | grep -vE '^Filesystem|tmpfs|udev' | awk '{ print $5 " " $1 }' | while read -r output;
do
  usep=$(echo "$output" | awk '{ print $1}' | cut -d'%' -f1  )
  partition=$(echo "$output" | awk '{ print $2 }' )
  if [ $usep -ge $ALERT ]; then
(
echo "From: $FROM"
echo "To: $ADMIN"
echo "Subject: $SUBJECT"
echo "Content-Type: text/html"
echo
 
echo "<html>"
 
echo "<p>Hostname : $HOSTNAME</p>"
echo "<p>Date : $(date)</p>"
 
echo "<p>Running out of disk space on: <strong>$partition</strong> <span style='color: rgb(255, 0, 0);'>${usep}</span>%</p>"
 
echo "<p><h4>Current disk space usage:</h4>"
echo "$(df -H | column -t)"
echo "</p>"
 
echo "<p><h4>Current memory usage:</h4>"
echo "$(free -m)"
echo "</p>"
 
echo "You own me one."
echo "<p>-- $0</p>"
 
echo "</html>"
echo
) | sendmail -f "$FROM" "$ADMIN"
 
  push_to_mobile "$0" "Alert out of disk space - $HOSTNAME [${DC_P}]
 
  Running out of disk space on: $partition (${usep}%)
 
  Current disk space usage:
  $(df -H | column -t)
 
  "
  fi
done