MUNIN Plugin WARN: MySQL InnoDB free tablespace

[Slatko]

Hello i installed yesteday the Munin Plugin.
It works great :D
But it shows me: MySQL InnoDB free tablespace WARN
Here is the Picture:


What it means?

 

[Defected]

I see the same weird behavior in a couple of servers and also on fresh installed machines. In an older ticket i've opened about this, support said that it's probably a munin bug. They were able to reproduce this behavior.

[email protected] [/etc/munin/plugins]# ./mysql_innodb
ERROR 1045 (28000): Access denied for user 'munin'@'localhost' (using password: YES)

I think there is a case opened (case 48107), so a fix might be released. Keep an eye on the changelog.

 

[SoftDux]

Does anyone know what causes this error, and how to fix it?

Is it an actual problem with the DB?

 

[fijumen]

Happened to me too, on a 2 new servers, must be a Munin bug, hope someone will update this thread after bug fix.

 

[cPanelTristan]

This warning should be disregarded. It is due to how Munin versus MySQL handle tablespace for InnoDB. By default, Munin throws a warning at 2GB free tablespace and critical alert at 1GB free tablespace. However, MySQL defaults to creating a 10MB autoexpanding tablespace. The tablespace can be verified with:

mysql -e "SHOW VARIABLES LIKE 'innodb_data_file_path'"

This means InnoDB will perpetually show <10MB of space (resulting in a permanent Munin warning) yet will always seamlessly autoextend as needed. The only "limit" in such a configuration is the partition that /var/lib/mysql is stored on. This render's the InnoDB free tablespace useless in an "autoextend" configuration.

The way to resolve is simply to disable the alerts. Create this file:

vi /etc/munin/plugin-conf.d/mysql_innodb

Place the following inside the file:

[mysql_innodb]
env.warning 0
env.critical 0

At that point, run the following commands:

/etc/init.d/munin-node restart
su munin -c /usr/bin/munin-cron

 

[alphawolf50]

Also, if you use innodb_file_per_table, there is no point even running this plugin. It is safe to:

# rm /etc/munin/plugins/mysql_innodb

This doesn't delete the actual plugin, only the symlink to the plugin. The actual plugin resides at:

/usr/share/munin/plugins/mysql_innodb.

Do not delete that one.

EDIT: after you've deleted the plugin, make sure you # service munin-node restart

 

[opentoe]

This Munin "bug" is from 2011, and is still happening today in 2013?

 

[Astral God]

This is not a bug, but a "bad" default configuration of Munin; please read posts #6 and #7.

 

[kamm]

I just installed munin using WHM > Manage Plugins. After the install I noticed the "MySQL InnoDB free tablespace" warning and have followed cPanelTristan's instructions in post #5.

Those commands ran OK until the last one...
su munin -c /usr/bin/munin-cron
which returns...
This account is currently not available.

Munin seems to be running OK and the warning has gone, but what about that last command? Perhaps something's changed since this post was written?

 

[Daky]

I am getting the same message.

Stopping Munin Node agents: [ OK ]
Starting Munin Node: [ OK ]
[email protected]*** [~]# su munin -c /usr/bin/munin-cron
This account is currently not available.

Please advise

 

[musioc]

Hello
Same error :
[email protected] [~]# su munin
This account is currently not available.

 

[cPanelMichael]

Hello

You can run the following commands instead:

su - munin --shell=/bin/bash
/usr/local/cpanel/3rdparty/perl/514/bin/munin-cron

Thank you.

 

[mahesh123]

hello

showing same warning ...


Thank you ..

 

[cPanelMichael]

showing same warning ...

Have you tried any of the solutions provided in this thread?

Thanks.

 

[RobinF28]

Hi,

This worked for me, thanks.

No more warnings showing at the MUNIN graph InnoDB free.

To help anyone wondering about the command flow, my terminal screen was something like this, FYI:

[email protected] [~]# mysql -e "SHOW VARIABLES LIKE 'innodb_data_file_path'"
+-----------------------+------------------------+
| Variable_name | Value |
+-----------------------+------------------------+
| innodb_data_file_path | ibdata1:10M:autoextend |
+-----------------------+------------------------+

[email protected] [~]# vi /etc/munin/plugin-conf.d/mysql_innodb

[email protected] [~]# cat /etc/munin/plugin-conf.d/mysql_innodb
[mysql_innodb]
env.warning 0
env.critical 0

[email protected] [~]# /etc/init.d/munin-node restart
Stopping Munin Node agents: [ OK ]
Starting Munin Node: [ OK ]

[email protected] [~]# su munin -c /usr/bin/munin-cron
This account is currently not available.

[email protected] [~]# su - munin --shell=/bin/bash
Attempting to create directory /home/munin/perl5
[email protected] [~]# /usr/local/cpanel/3rdparty/bin/munin-cron
[email protected] [~]#

[email protected] [~]# logout
[email protected] [~]#

 

[cPanelMichael]

I am happy to see you were able to address the issue. Thank you for updating us with the outcome.

 

[jmcguirl]

Hi,

This worked for me, thanks.

No more warnings showing at the MUNIN graph InnoDB free.

To help anyone wondering about the command flow, my terminal screen was something like this, FYI:

[email protected] [~]# mysql -e "SHOW VARIABLES LIKE 'innodb_data_file_path'"
+-----------------------+------------------------+
| Variable_name | Value |
+-----------------------+------------------------+
| innodb_data_file_path | ibdata1:10M:autoextend |
+-----------------------+------------------------+

[email protected] [~]# vi /etc/munin/plugin-conf.d/mysql_innodb

[email protected] [~]# cat /etc/munin/plugin-conf.d/mysql_innodb
[mysql_innodb]
env.warning 0
env.critical 0

[email protected] [~]# /etc/init.d/munin-node restart
Stopping Munin Node agents: [ OK ]
Starting Munin Node: [ OK ]

[email protected] [~]# su munin -c /usr/bin/munin-cron
This account is currently not available.

[email protected] [~]# su - munin --shell=/bin/bash
Attempting to create directory /home/munin/perl5
[email protected] [~]# /usr/local/cpanel/3rdparty/perl/514/bin/munin-cron
[email protected] [~]#

[email protected] [~]# logout
[email protected] [~]#

As this port gets older, the very last munin command should be changed to:

/usr/local/cpanel/3rdparty/bin/munin-cron

It is a symlink that always points to the latest version of munin-cron. Just my two cents.

 

[kitchin]

As this port gets older, the very last munin command should be changed to:

/usr/local/cpanel/3rdparty/bin/munin-cron

It is a symlink that always points to the latest version of munin-cron. Just my two cents.

No symlink here. Just look for the latest perl in
/usr/local/cpanel/3rdparty/perl

 

[Michael-Inet]

Hi All,

Really old post, here’s the instructions as of today. The official instructions are at:

Munin shows "MySQL InnoDB free tablespace" critical alert

Symptoms Munin service monitor can show a critical alert, "MySQL InnoDB free tablespace". Description This warning should be disregarded. It is due to how Munin handles tablespace for InnoDB...

support.cpanel.net

but, they give you ‘bad’ correct ‘Workaround’ instructions.

Correct "Workaround" for cPanel: Remove the symlink to the plugin so it’s not triggered.


Verify your server is "Okay"

# mysql -e "SHOW VARIABLES LIKE 'innodb_data_file_path'"
+-----------------------+------------------------+
| Variable_name | Value |
+-----------------------+------------------------+
| innodb_data_file_path | ibdata1:12M:autoextend |
+-----------------------+------------------------+

Apply "Workaround"

*'s are the commands you need, everything else is optional.

[email protected] [~]# ll /etc/munin/plugins/mysql_innodb
lrwxrwxrwx 1 root root 59 Oct 24 12:54 /etc/munin/plugins/mysql_innodb -> /usr/local/cpanel/3rdparty/share/munin/plugins/mysql_innodb

* [email protected] [~]# rm /etc/munin/plugins/mysql_innodb
rm: remove symbolic link ‘/etc/munin/plugins/mysql_innodb’? y

* [email protected] [~]# systemctl restart munin-node

[email protected] [~]# systemctl status munin-node
? munin-node.service - Munin
   Loaded: loaded (/etc/systemd/system/munin-node.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2020-10-24 13:29:58 CDT; 39s ago
  Process: 9560 ExecStart=/usr/local/cpanel/3rdparty/perl/530/sbin/munin-node (code=exited, status=0/SUCCESS)
  Process: 9559 ExecStartPre=/usr/bin/chown -R munin:munin /var/run/munin (code=exited, status=0/SUCCESS)
  Process: 9558 ExecStartPre=/usr/bin/mkdir -p /var/run/munin (code=exited, status=0/SUCCESS)
 Main PID: 9561 (munin-node)
   CGroup: /system.slice/munin-node.service
           +-9561 /usr/local/cpanel/3rdparty/perl/530/bin/perl -wT /usr/local/cpanel/3rdparty/perl/530/sbin/munin-node

Oct 24 13:29:58 srv10.srv10-inet-design.com systemd[1]: Starting Munin...
Oct 24 13:29:58 srv10.srv10-inet-design.com systemd[1]: Started Munin.

Additional Information:

Install Munin

WHM »Home »cPanel »Manage Plugins
>> Install Munin for cPanel

Check Munin

WHM »Home »Plugins » Munin Service Monitor