Bug #30820 Monitor can't get disk information

Description:
I created the custom rule like these.

[Expression]
%disk_reads% > THRESHOLD

[Thresholds]
Critical Alert: 9000
Warning Alert: 3000
Info Alert: 1000

[Variable Assignment]
variables: %disk_reads%
Data Item: os:disk:disk_reads
Instance: /

But this error was written in "mysql-service-agent.log".

    2007-09-05 17:11:00: (critical) disk-get failed for c0d0p1: 2

This looks like NMAS can't get information.

How to repeat:
Create the rule as described previously.

Read the "mysql-service-agent.log".

Thank you for the report.

Verified as described.

Added to "Known Issues".

Also, we only report information on / if the mysqld datadir is not on root this value is not very useful.

Investigate instance iteration

Verified fixed in build 2.0.3.7134.

NOTES: The value to be used in the 'Instance' field is different if we are using Data Item 'os:disk:disk_reads' vs 'os:fs:fs_unused'. Mainly notice the difference between using 'disk' and 'fs'. The following Variable Assignment examples show what works for these two type names.

Example 1 (on Mac OSX):
  Variable: %disk_reads%
  Data Item: os:disk:disk_reads
  Instance: /dev/disk0s2

Example 2 (on Mac OSX):
  Variable: %fs_unused%
  Data Item: os:fs:fs_unused
  Instance: /

Example 3 (on Windows XP):
  Variable: %fs_unused%
  Data Item: os:fs:fs_unused
  Instance: C:\

--

An entry was added to the 2.0.3 changelog:

When a custom rule requiring disk information was created, for example:

[Expression]
%disk_reads% > THRESHOLD

[Thresholds]
Critical Alert: 9000
Warning Alert: 3000
Info Alert: 1000

[Variable Assignment]
variables: %disk_reads%
Data Item: os:disk:disk_reads
Instance: /
The following error was written to the file mysql-service-agent.log:

2007-09-05 17:11:00: (critical) disk-get failed for c0d0p1: 2
It therefore appeared that the Service Agent was not able to obtain the required information.