We have a deployment with what I would call an Enterprise Cloud Provider. It's VMWare Infrastructure 3.5.x and includes VMotion / VMWare HA instances, etc.
At Provider 1 VMWare Tools was installed:
- vmware-guestd is running and;
- at least two kernel modules are loaded, vmmemctl & vmhgfs
Provider 1 does nightly VM Snapshots.
We are beginning a new deployment at Provider 2 (also an Enterprise Cloud Provider). They did not install VMWare Tools. Provider 2 does not do nightly VM Snapshots but rather file-system backups (using an agent).
From my reading it seems like at the very least VMWare Tools should be installed for the Memory Balloon Driver (vmmemctl) and from reading sources like this one it suggests that certain VirtualCenter management operations also depend upon VMWare Tools being installed in the Linux guest.
Note that all of our instances are headless (default runlevel is 3) and RHEL.
It is hard to find authoritative information on this question and the aforementioned source is somewhat dated.
Can someone shed some light on this? What are the factors/criteria that would lead to an answer in the affirmative or negative?
TIA
Cheers
You should also have the tools loaded for ease of guest shutdown and power management. Being able to shut the guest operating system down from the Vcenter server or infrastructure client is handy.
I'd be tempted to load all of the vmtools, not only will the guest be less of a load on the host but it's a great way of getting your time right.
In addition to the better power/cpu/memory management that other answers have mentioned, the tools also give you the vmxnet* and pvscsi/something else/ device drivers that, ostensibly, provide better performance for networking and IO compared to emulating a "real" device.
In modern times it is better to install
open-vm-tools
, e.g. on Debian or Ubuntu:From the package description:
See also http://open-vm-tools.sourceforge.net/
Installing the tools will allow for better cpu and memory management. For example, Transparent Page Sharing & Memory Ballooning.
Understanding Memory Resource Management in VMware (pdf)