From ef010e6456b796b5fc7bcf33793255ccd89b53a6 Mon Sep 17 00:00:00 2001 From: "Michael J. Carmody" Date: Tue, 24 Sep 2019 16:12:09 +1000 Subject: feature: adding notes for running on vmware around contending memory and memory management in low memory situations --- docs/appendix/vyos-on-vmware.rst | 32 ++++++++++++++++++++++++++++++++ docs/index.rst | 1 + 2 files changed, 33 insertions(+) create mode 100644 docs/appendix/vyos-on-vmware.rst (limited to 'docs') diff --git a/docs/appendix/vyos-on-vmware.rst b/docs/appendix/vyos-on-vmware.rst new file mode 100644 index 00000000..85b4cef5 --- /dev/null +++ b/docs/appendix/vyos-on-vmware.rst @@ -0,0 +1,32 @@ +.. _vyosonvmware: + +Running on VMWare ESXi +##################### + +ESXi 5.5 or later +**************** + +.ova files are available for supporting users, and a VyOS can also be stood up using a generic Linux instance, and attaching the bootable ISO file and installing from the ISO +using the normal process around `install image`. + +.. NOTE:: There have been previous documented issues with GRE/IPSEC tunneling using the E1000 adapter on the VyOS guest, and use of the VMXNET3 has been advised. + +Memory Contention Considerations +-------------------------------- +When the underlying ESXi host is approaching ~92% memory utilisation it will start the balloon process in s a 'soft' state to start reclaiming memory from guest operating systems. +This causes an artifical pressure using the vmmemctl driver on memory usage on the virtual guest. As VyOS by default does not have a swap file, this vmmemctl pressure is unable to +force processes to move in memory data to the paging file, and blindly consumes memory forcing the virtual guest into a low memory state with no way to escape. The balloon can expand to 65% of +guest allocated memory, so a VyOS guest running >35% of memory usage, can encoutner an out of memory situation, and trigger the kernel oom_kill process. At this point a weighted +lottery favouring memory hungry processes will be run with the unlucky winner being terminated by the kernel. + +It is advised that VyOS routers are configured in a resource group with adequate memory reservations so that ballooning is not inflicted on virtual VyOS guests. + + + + + +References +---------- + +https://muralidba.blogspot.com/2018/03/how-does-linux-out-of-memory-oom-killer.html + diff --git a/docs/index.rst b/docs/index.rst index 58461850..59b74b38 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -43,6 +43,7 @@ as a router and firewall platform for cloud deployments. appendix/troubleshooting.rst appendix/examples/index.rst appendix/commandtree/index.rst + appendix/vyos-on-vmware.rst appendix/vyos-on-baremetal.rst appendix/migrate-from-vyatta.rst -- cgit v1.2.3