RAM utilisation | Home Assistant | Page 1

remote gale May 1, 2025, 8:58 AM

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For years I ran Home Assistant on a 4GB Raspberry Pi, and it was always hitting close to max RAM utilisation. About a year ago I switched to a virtual machine on Proxmox, using the HA OS method. I assigned it 8GB and the RAM use was again close to max RAM. Yesterday, I increased it to 16GB to see what would happen and it seems it was again getting close to max RAM utilisation although it then backed off a little bit. I don't have a big install by any stretch. I don't really notice any significant delays in performance now, nor did I when it ran on 4GB.

I am wondering why so much RAM is being used. Is it perhaps like Windows, where the OS takes up all the RAM it can get for caching of local files to speed things up? Should I just keep reducing it until I start noticing things slowing down?

I would be very curious to get some pointers on what could be causing all the RAM to be gobbled up!

Thanks in advance for your patience.

red hemlock May 1, 2025, 10:07 AM

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it's being gobbled up by cache. most modern OSes will cache as much as possible and utilize as much memory as possible. unless you know you are going to be doing memory heavy stuff like running databases alongside HA 4GB memory is probably enough

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i've got HAOS running in a VM in Proxmox and I've given it 4GB, which it is using most of. looks bad, right?

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but if I actually look at the Hardware page in HA, it's really only using a little more than a gig and the rest is just cache

full stratus May 1, 2025, 5:08 PM

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Use the glances addon to see the actual memory usage in detail.
The PVE stats (depending on a lot of variables), as explained above, include all the memory used. Even cache and buffers: https://www.google.com/search?q=proxmox+wrong+memory+usage+site:forum.proxmox.com

smoky anvil May 1, 2025, 7:09 PM

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red hemlock i've got HAOS running in a VM in Proxmox and I've given it 4GB, which it is usin...

proxmox lies to you!

full stratus May 1, 2025, 7:10 PM

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Just a matter of perspective.

remote gale May 3, 2025, 3:18 AM

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This is all very useful information. Thank you guys so much for sharing this information. My HA is reporting 1.4GB in use, while the Proxmox VM says 14 of the allocated 16GB is in use.

<offtopic>The same principle happened with my fileserver vm, for which Proxmox reported almost all of the allocated 16GB was in use as well. After looking, I found that free gives good information and it turns out it was ACTUALLY using less than 1GB!</offtopic>

Long story short ... I upgraded my memory from 16GB to 64GB for no reason, and wasted a bunch of money in doing so.

I'm super annoyed with myself.

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But super happy with the insights you guys have provided 🙂

smoky anvil May 3, 2025, 3:26 AM

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remote gale This is all very useful information. Thank you guys so much for sharing this inf...

now you can run other random services!
also some further reading here

remote gale May 3, 2025, 3:27 AM

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I never know what to run! Haha

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hey anybody want to buy 64GB of DDR4 memory? 😉

smoky anvil May 3, 2025, 3:28 AM

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check out selfhosted reddit and the selfhosted weekly newsletter for inspiration 🙂

remote gale May 3, 2025, 3:29 AM

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hehe, thanks

smoky anvil May 3, 2025, 3:29 AM

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i spin up random stuff to experiment all the time. sometimes i continue with it and sometimes i dont

remote gale May 3, 2025, 3:29 AM

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i love my little dinky homelab .... but i will admit to feeling like a total n00b for having bought all this RAM when the 16GB I had was more than double what i needed already

smoky anvil May 3, 2025, 3:30 AM

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lets be real, it wont be the last mistake you make. treat it as a learning experience

remote gale May 3, 2025, 3:30 AM

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true 🙂

smoky anvil May 3, 2025, 3:31 AM

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there are plenty of things i have done and bought that i wouldn't recommend to people after doing them

remote gale May 3, 2025, 3:33 AM

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part of the fun, as you said

#RAM utilisation