Re: [gentoo-user] virtualbox in headless configuration broken after update: delayed echo [ RESOLVED, kinda ]

[n952162]

On 06/17/20 06:48, J. Roeleveld wrote:
> On Tuesday, June 16, 2020 11:08:23 PM CEST n952162 wrote:
>> On 06/16/20 22:36, J. Roeleveld wrote:
>>>
>>> Are these Virtualbox VMs critical?
>>> If yes, I would suggest migrating them to a more reliable virtualisation
>>> technology.
>>>
>>> I do not consider Virtualbox suitable for anything but a desktop based VM
>>> method for a quick test or simulation.
>>>
>>> Gor anything serious, I would suggest Xen, KVM or VMWare.
>>>
>>> --
>>> Joost
>> Well, no, they're really not critical, but your comment surprises me.
>> I've been using vbox for years, on various assignments, and never
>> encountered anything else.  Can you say a word or two to that, or
>> provide a URL?  Which free vm is "the best"?
> I never bothered bookmarking URLs about this, but can elaborate on my
> reasoning and experience.
>
> Virtualbox is a nice product and I do use it when it is convenient. It is
> perfect for quickly starting a VM to test something. It integrates nicely with
> the desktop to be able to quickly copy/paste data across and also easy to
> connect to the filesystem on the host.
>
> This also mentions the reason why it is NOT suitable for actual production
> use. It is a virtualisation tool for a desktop.
>
> If you want your VMs to run as fast and stable as possible, you want the host
> to be as minimal as possible. This means:
> - it runs headless (no GUI, just text) and the host has only 1 task: Run VMs.
> - it doesn't contain anything else (only exception is stuff for monitoring)
>
> Virtualbox does not (afaik) support block-devices for VMs. It only supports
> file-based disks. This is fine as it allows you to "quickly" move these to
> different storage. But it adds another layer between the hardware and VM
> (filesystem on the host) which adds it's own write-caching and potential
> corruption (I have had this on several occasions).
>
> The virtualisation systems I mentioned in my previous email (Xen, KVM, VMWare)
> all support block-devices and sit as close to hardware as is possible. In the
> case of VMWare, I am talking about the server product, not the desktop
> product. The VMWare desktop product has the same problems as VirtualBox.
>
> As for which free one is best, I am reluctant to answer specifically as both
> Xen and KVM are good.
>
> Personally, I use Xen. I have been using it since one of the 2.x versions and
> KVM didn't exist back then.
> Xen has the hypervisor in a small "kernel" and the host runs as a VM with full
> privileges. You can add additional privileges VMs to provide storage, further
> seperating tasks between VMs.
> Citrix also provides a free version of their Xen-product which can be managed
> remotely, but their remote-tool is windows-only last time I checked. I run Xen
> on top of Gentoo and manage everything from the CLI.
>
> KVM runs inside a Linux kernel and this instance automatically is the host. (I
> don't know enough to properly compare the 2, there are plenty of resources
> about comparisons online, most are biased to one or the other)
>
> Both Xen and KVM can be managed with other tools like virt-manager. I don't as
> I don't like the way those tools want to manage the whole environment.
>
> As for use of these systems, when only looking at companies where I have
> experience with:
>
> - VMWare is often used for virtualising servers
> - Xen (Citrix) is often used to provide Virtual Desktop to users
> - KVM is used by most VPS providers
> - Virtualbox is used for training sessions
>
> I have not come across MS HyperV outside of small businesses that need some
> local VMs. These companies tend to put all their infrastructure with one of
> the big cloud-VM providers (Like AWS, Azure, Googles,...)
>
> --
> Joost
>
>

Thank you for this excellent survey/summary.  It tells me that vbox is
good for my current usages, but I should start exposing myself to Xen as
a possible migration path.