LXC - Container memory usage is above 90%

[mjb2000]

Hi all

I have been experimenting with LXC, in particular OpenMediaVault running on Debian 7 in a container and I've found that after using the container for a while Proxmox shows the memory usage above 90% (sometimes 100%), but within the container itself running the free command shows that most of this memory usage is just the IO cache.

My question is, if I had a total of 4GB ram on the host and ran 6 containers each with a maximum of 1GB each, would some of the machines be starved of RAM they actually need to run processes whilst other machines are holding on to RAM as IO cache? (or will the IO cache from other machines be released to free up RAM for any container that truly needs it?)

Thanks

Matt

 

[manu]

I don't think LXC has dynamic memory allocation activated, so if you're host in taking lots of RAM for I/O caching, it should not impact the memory of the other guests.

However it could be possible that the access to the storage device slows itself down processes in the others LXCs, leaving them waiting for I/O.

 

[mjb2000]

Ah - OK, thanks for letting me know. I'll make sure I set all my limits appropriately.