VM Crash and no logs
- Thread starter roberne
- Start date
Looking at your hosts graphs the hosts RAM usage slowly climbed up to 99%, your host was already swapping as hell and swap was full too so OOM kicked in and killed your VM. You should look at your hosts syslog file for OOM mesages. Make sure your host always got enough available memory left (I try to keep 10-20% free). So looks to me that the host just ran out of RAM.
You could:
You could:
- buy more RAM for your host
- if you use ZFS limit your ARC size
- look that you don't give your VMs more RAM they actually really need or the guests will fill up all the RAM with caches. If Proxmox shows that your guest is low on free RAM that doesn't mean that the guest is really running out of memory. You should run "free -h" inside the guest and look how much RAM is actually "available" and don't look on the guests memory usage graph Proxmox is presenting you. I would bet you can easily reduce the guests RAM from 18 to 8GiB without any problems because most of that RAM is just used for page file caching. Look here for a better unterstanding.
- enable ksmtuned for memory deduplication. Will slowdown your host but can save you some RAM if you got alot of the same VMs or services running. Here this saves me 9-11GB of 64GB.
- enable ballooning and give your VM a "min RAM" of 8GB or something like that. If your host will run out of RAM (used RAM >80%) ballooning will kick in and limit the VM to 8GB RAM so it is forced to drop the caches or kill some processes if it is using more than 8GB.
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1-all pcs on host uses 29gb ram host have 32gb,
2- ZFS and ARC size please speak english xD i'm so new if u have any guide of what is it
3- my guest only needs 10gb but it fills up i dont know how do that, and i see that proxmox shows more ram usage than machine shows
4- please a guide
5- guide too xD sorry i'm really newbie
PHOTOS:
free -h
panel
2- ZFS and ARC size please speak english xD i'm so new if u have any guide of what is it
3- my guest only needs 10gb but it fills up i dont know how do that, and i see that proxmox shows more ram usage than machine shows
4- please a guide
5- guide too xD sorry i'm really newbie
PHOTOS:
free -h
panel
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You might be pushing too close to the limit on host.
On my first proxmox box I had a few unexplained reboots, was no evidence of kernel panics.
Then I added a swap and they stopped confirming was oom, but then several months later there was odd behaviour with the swap so I ended up just managing my ram better without swap. I think you should give a higher margin for free memory.
On my first proxmox box I had a few unexplained reboots, was no evidence of kernel panics.
Then I added a swap and they stopped confirming was oom, but then several months later there was odd behaviour with the swap so I ended up just managing my ram better without swap. I think you should give a higher margin for free memory.
Your host needs RAM too. And there is always virtualizationoverhead. So if you give 29GB to your VMs your might use over 32GB of RAM.
Its really not that hard to use google to look up what ZFS is. Did you read the proxmox documentation at all? Its everywhere in the documentation and a complete chapter on how to manage und optimize ZFS. By default ZFSs ARC will use up to 50% of the total RAM, so 16GB RAM might be used by ZFSs ARC if you are using ZFS as your storage.
Looking at your free -h you guests services use 2,8GiB RAM + 5.0GiB for caching. That caching will grow until there is no free momory. Did you read the link I gave you? Its explained there. So you give your VM way too much RAM because Linux will eat all RAM you throw at it for caching.
Its all in the documentation "10.2.6. Memory".
And you really should read the whole thing atleast once to understand what you are doing.
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