July 28, 20178 yr Author I mean limit the memory that unRAID can use.I want to leave 8GB memory to my VMs Edited July 28, 20178 yr by TheBlueKingLP
July 28, 20178 yr Community Expert 21 minutes ago, TheBlueKingLP said: I mean limit the memory that unRAID can use.I want to leave 8GB memory to my VMs Still not sure why you want to limit unRAID. UnRAID does not have that much RAM dedicated to it - most of its usage is dynamic depending on what else is running in the system. When you start a VM the memory it is set to use will be allocated to it, and when there is no VM then it can be dynamically used at the Linux level for things like caching I/O. Note that when you start a VM there can be a considerable overhead (~ 1GB) on top of the amount you specify for the VM to support the emulation within KVM so make sure you take that into account when working out how much RAM to give any particular VM. Also note that running VMs cannot share memory - it is allocated when any particular VM starts and not available for anything else to use until the VM is closed.
July 29, 20178 yr Author 19 hours ago, itimpi said: Still not sure why you want to limit unRAID. UnRAID does not have that much RAM dedicated to it - most of its usage is dynamic depending on what else is running in the system. When you start a VM the memory it is set to use will be allocated to it, and when there is no VM then it can be dynamically used at the Linux level for things like caching I/O. Note that when you start a VM there can be a considerable overhead (~ 1GB) on top of the amount you specify for the VM to support the emulation within KVM so make sure you take that into account when working out how much RAM to give any particular VM. Also note that running VMs cannot share memory - it is allocated when any particular VM starts and not available for anything else to use until the VM is closed. I want to limit menory because unraid using over 8gb memory
July 29, 20178 yr Typically the OS will use its memory for best use. Having it sit idle off to the side does no one any good. When you have a new demand for memory, this may require the OS to reduce its memory use in another area (e.g., disk buffers), to provide that memory for another need. You are able to dedicate swaths of memory to VMs. Once allocated, the unRAID OS will not have access to that memory until the VM ends. That's about all the control you get over the OSes using memory.
July 29, 20178 yr Community Expert 54 minutes ago, TheBlueKingLP said: I want to limit menory because unraid using over 8gb memory The base requirement for unRAID is something like 1-2GB. Is there anything that makes you think unRAID is using more than that for core functionality that locks down RAM? It is standard on Linux based systems that if you have unused RAM available to start using it for disk caching to improve overall performance. If an app (e.g. a VM) needs it then memory used for disk caching will be released and be available to pass to the app.
July 30, 20178 yr Author 23 hours ago, itimpi said: The base requirement for unRAID is something like 1-2GB. Is there anything that makes you think unRAID is using more than that for core functionality that locks down RAM? It is standard on Linux based systems that if you have unused RAM available to start using it for disk caching to improve overall performance. If an app (e.g. a VM) needs it then memory used for disk caching will be released and be available to pass to the app. but when i start a vm with more memory,it give me an error: Quote Execution error internal error: process exited while connecting to monitor: 2017-07-30T05:37:23.900088Z qemu-system-x86_64: cannot set up guest memory 'pc.ram': Cannot allocate memory
July 30, 20178 yr Maybe try posting your system diagnostics "Tools -> Diagnostics" that includes when you try starting your VM and get the error. That should help the experts here figure out what's going on.
July 30, 20178 yr At least post how much memory you have installed and what you've got allocated to VMsSent from my LG-H815 using Tapatalk
August 2, 20178 yr That sounds about right. Are you trying to allocate even more memory to the VM than the 12GB you are allocating now?
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