Comparing items with other items or previous values

[crlf]

Hi,

I'm trying to implement a trigger when a value suddenly drops or rises (think free space or ambient temperature). I'm thinking about comparing the last value with a value from the previous day, but I don't know how to accomplish this.

Theoretically, it should be "prev_free_space - current_free_space > some_value", but trigger expressions don't seem to support such a thing. Do they?

Is there any other way to do this using some feature that I don't know about? I'm using Zabbix 2.0.5.

Thanks.

[eskytthe]

You could e.g. use the avg function, with the time_shift parameter

https://www.zabbix.com/documentation/2.0/manual/appendix/triggers/functions

BR
Erik

[crlf]

But can I do "average_some_time_ago > current_value - some_threshold"?

From the docs it doesn't seem to be possible to compare two items with each other in the same trigger...

[eskytthe]

Yes as far as I know - Take a look at example 11 (and operators in the start of the page):

https://www.zabbix.com/documentation/2.0/manual/config/triggers/expression

Br
Erik

[crlf]

Thanks, that worked.

I ended up with this rule:

{server:vfs.fs.size[E:,free].last(0,1d)}-{server:vfs.fs.size[E:,free].last(0)}>10G

[lustigerpinguin]

Permanent warning

Hi,

I used a similar syntax for a trigger.
(my test: {zabbix-test.dev.nsynd.com:vfs.fs.size[/boot,pfree].avg(1200,300)}-{zabbix-test.dev.nsynd.com:vfs.fs.size[/boot,pfree].avg(300)}>3)

The problem: after a short time: the problem isn't available! What can I do for a permanent warning on the main page (Dashboard)?

Thanks

Regards
lustigerpinguin