Creating a percentage based off of a pools total dataset storage?

[DoItAgainSteelyDan]

Hello,

I am trying to create an item and trigger inside Zabbix (7.2 version, but would like it to work 6.0+)


(As we can see they are not reflecting total amount used 2.46gb)

zfs.test.avail.bytes and zfs.test.used.bytes, I was able to get their OIDs using "snmpwalk -v2c -c public truenas-ip"



I want this percentage to reflect in Zabbix from TrueNAS using zfs.test.avail.bytes and zfs.test.used.bytes. I want a trigger in place that says when it is above >X%

I thought this would work:

100 * last("zfs.test.used.bytes") / (last("zfs.test.used.bytes") + last("zfs.test.avail.bytes"))


But I am getting bad output.



Goal:

Monitor storage pools, when datasets make the pool full an item in zabbix will make a trigger go off saying it is above >X%

[salavie]

100 * last(//zfs.test.used.bytes) / (last(//zfs.test.used.bytes) + last(//zfs.test.avail.bytes))

[DoItAgainSteelyDan]

Thanks, this worked. Any tips for remembering how to do syntax correctly?

[DoItAgainSteelyDan]

Also, I'm trying to monitor the total percentage used for a pool, meaning total data within the datasets combined for total sum.
I'm getting an offset on the calculations, in TrueNAS it will be at 94% storage used, while in Zabbix it is around 91%~. how am I able to monitor the raw data that TrueNAS is showing in its dashboard to show in the Zabbix Dashboard.

Examples:



It's two 15GiB hard drives in mirror mode. It reflects as 12.5GiB in Zabbix. I assume that it is not taking into consideration the partition data or metadeta?

Thank you for the help

[salavie]

Calculated items

https://www.zabbix.com/documentation/6.0/zh/manual/config/items/itemtypes/calculated

I don't know about nas

[Brambo]

Also, I'm trying to monitor the total percentage used for a pool, meaning total data within the datasets combined for total sum.
I'm getting an offset on the calculations, in TrueNAS it will be at 94% storage used, while in Zabbix it is around 91%~. how am I able to monitor the raw data that TrueNAS is showing in its dashboard to show in the Zabbix Dashboard.

Examples:



It's two 15GiB hard drives in mirror mode. It reflects as 12.5GiB in Zabbix. I assume that it is not taking into consideration the partition data or metadeta?

Thank you for the help

The difference could be GB vs GiB. To know that for sure look at the raw values and do some /1000 vs /1024 on those values and compare it with your expected result. If Zabbix gets the wrong data presented then Zabbix isn't the issue but maybe you can fix it with a pre-processing step for correction.

[DoItAgainSteelyDan]

The difference could be GB vs GiB. To know that for sure look at the raw values and do some /1000 vs /1024 on those values and compare it with your expected result. If Zabbix gets the wrong data presented then Zabbix isn't the issue but maybe you can fix it with a pre-processing step for correction.

I've figured out a way to monitor the pools storage percentage, it reflects the number in TrueNAS.



One of the roadblocks were the percentages were off. I learned it's because TrueNAS reports in GiB and Zabbix reports in GB. There is a difference in byte size.



The expression is



((last(//truenas.zpool.used[tank]) / last(//truenas.zpool.size.total[tank])) * 100) * 1.032967



which calculates a ZFS pool usage percent and applies a coorection factor (1.032967 offset to fix the difference in byte size converting from GiB to GB. )



It will monitor and update the pools storage percentage, however I noticed that if I delete data out of an SMB, the storage doesn't change right away. If there are snapshots with the deleted data, then it still reflects in both TrueNAS and Zabbix as the last known highest percentage. Scrubbing the pool did not seem to update this, it was only until I deleted the snapshots with the data on them would the storage percentage go back down in TrueNAS/Zabbix.

Why is this? Is there anyway to show it without having to delete snapshots? Maybe more of a TrueNAS forums question.

Thank you.