Monitoring memory usage using ZFS


Active Member
Jan 23, 2010
Stockholm Sweden
Am trying out Proxmox+ZFS on the same machine. Am new to ZFS.
Am monitoring my server with Zabbix and my memory usage is 90%. It is of course mostly ZFS cache but how do I monitor when am running out of memory? Will ZFS always be at 90% so I can set my alarms at 95%?
How do you guys monitor RAM usage when running virtual machines and ZFS on the same machine? How can I get insight into how much memory is my virtual machines using and how much is ZFS using? Proxmox WebGUI only shows total RAM usage without any insight on what is using the memory. Kinda bad because proxmox promotes ZFS so the WebGUI should in my opinion show better statistics around RAM usage in the summary page.


Famous Member
Jun 30, 2020
By default ZFS will use up to 50% of your RAM for caching. Look at memory "available" and not at memory "free". On your host you can check it with "free -h" and zabbix is collecting it as "Available memory" and "Available memory in %". Its no problem if "free" memory is down nearly 0% but "available" memory should always be a bit available (20% or so).
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Active Member
Dec 20, 2018
The same issue with NetData monitoring alarms.
IMHO it's better to switch it off. RAM must to work hard. ZFS is using RAM for the good things.
@Dunuin thanks for advice, I'll try to monitor available memory.


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