[SOLVED] How to alert on disk space?

[rogierl]

Hey! Happy Proxmox user here (for my home-server). It's very stable and running a couple of VMs for months now. One of my projects is to have metrics on all kinds of systems, f.e. my solar panels, but also my (virtual) servers. So what I did:

• Running prometheus in a container
• Added a couple of node_exporters
• Running grafana in a container, pointing it to prometheus

So far so good.

Now my question: I want to measure the percentage of free disk space on the PVE host. In the GUI, I see the following piecies:

1. LVM: 88% usage
2. LVM-thin: 68% usage

Now my question is: what is the difference here?
Where should I setup an alert for? For LVM or LVM-thin usage?

 

[Dunuin]

The bottom pictures shows you how much of the LVM is allocated. 127.49GB is size the partition sda3 and 88% of that is used for VGs and 15.84GB is unallocated so LVM can use it for snapshots and so on.

Inside the VGs you got your LVs for data (VM/LXC images), swap and root (your proxmox OS, ISOs, Backups and so on).
So the upper picture should show you that 70.32GB is available for VMs/LXCs and 68% of that is already used by VMs/LXCs.

You should read a bit on how LVM is working. Commands like lvs and vgs are useful if you want to know what uses how much space.

 

[rogierl]

Thanks! All clear now.

 

[DerDanilo]

You may use the API or local ssh wrapper for that. You need to build your own filter to do that but it's a start and should be simple. I may even build a simple bash script some day and publish it to Github. If you decide to do it fast, don't hesitate to commit our script. Thanks!

root@node ~ # pvesh get /nodes/node/storage --storage SSD1 --output-format yaml --human-readable 1
---
- active: 1
  avail: 741010707579
  content: images
  enabled: 1
  shared: 0
  storage: SSD1
  total: 966367641600
  type: lvmthin
  used: 225356934021
  used_fraction: 0.233199999999876

root@node ~ # pvesh get /nodes/node/storage --storage SSD1 --output-format yaml --human-readable 1 | grep -i used_fra
  used_fraction: 0.233199999999876

root@node ~ # pvesh get /nodes/node/storage --storage SSD1 --output-format yaml --human-readable 1 | grep -i avail
  avail: 741010707579

 

[andreviana]

Hello @DerDanilo,
Do you know how to get that "avail" output in GiB? Or how to specify the unit?

Thanks in advance,

 

[DerDanilo]

Hello @DerDanilo,
Do you know how to get that "avail" output in GiB? Or how to specify the unit?

Thanks in advance,

I don't. Currently I am using checkmk because of the lack of time to write some checks myself.