Filesystem usage not show correctly when lvm logical volume is too long

short description

If lvm logical volume is too long, the disk usage is not show correctly

correct behaviour

The filesystems usage must be show correctly also in this case

environment

Server OS: (centos 6)
Server OS version: CentOS release 6.9 (Final)
ISPConfig version: (3.1.11)

On my system the df command used from ispc show this output:

[root@s-ispc-c3 ispconfig]# df -hT -x simfs
Filesystem           Type   Size  Used Avail Use% Mounted on
/dev/mapper/vg_sispcc1-lv_root
                     ext4   7,7G  2,9G  4,5G  39% /
tmpfs                tmpfs  1,9G     0  1,9G   0% /dev/shm
/dev/sda1            ext4   477M  180M  272M  40% /boot
/dev/mapper/vg_sispcc1-lv_var
                     ext4   136G  120G  9,2G  93% /var

Then the usage of root and var FS is not reported into disk usage page

proposed fix

Use the -P option in 'df' command to solve the issue:

   -P, --portability
          use the POSIX output format

This is ispc df output with -P option:

[root@s-ispc-c3 ispconfig]# df -PhT -x simfs
Filesystem                     Type   Size  Used Avail Use% Mounted on
/dev/mapper/vg_sispcc1-lv_root ext4   7,7G  2,7G  4,6G  37% /
tmpfs                          tmpfs  1,9G     0  1,9G   0% /dev/shm
/dev/sda1                      ext4   477M  180M  272M  40% /boot
/dev/mapper/vg_sispcc1-lv_var  ext4   136G  120G  9,1G  93% /var

This is proposal patch

--- /usr/local/ispconfig/server/lib/classes/cron.d/100-monitor_disk_usage.inc.php.orig  2018-02-02 15:19:28.778921392 +0100
+++ /usr/local/ispconfig/server/lib/classes/cron.d/100-monitor_disk_usage.inc.php       2018-02-02 15:53:11.169589836 +0100
@@ -74,7 +74,7 @@
                $app->uses('getconf');
                $web_config = $app->getconf->get_server_config($conf['server_id'], 'web');
 
-               $dfData = shell_exec('df -hT -x simfs | awk \'!x[$1]++\' 2>/dev/null');
+               $dfData = shell_exec('df -PhT -x simfs | awk \'!x[$1]++\' 2>/dev/null');
 
                // split into array
                $df = explode("\n", $dfData);

With this patch and after run /usr/local/ispconfig/server/cron.sh the disk usage is show correct

Thanks

Dario Lesca