So, can you some give me advice how I may sale VPS on same box where is already installed Ensim and Modernbill (VPS, shared and reseller on same Box? - with Large CPU and allocated RAM for VPS);
In other way:
did I must reinstall OS and after that install some new Open source VPS solution and re-install Ensim - if SOME (WHICH- I DONT KNOW) open source VPS Cp can work like that with Ensim? ( I need to not demage main website and modernbill installation - MySQL Db?)
If you already have modernbill and Ensim installed on your server I would strongly discourage installing any of the above VPS software. I'd reccomend getting a new server to install your VPS software on, then migrate your existing applications into VPS accounts on the new box if you only want to have one. At the end of the day, you'll probably want more than 1 box if you're going to be selling VPS accounts anyways.
Most control panels that are installed on a Linux OS have tons of dependancies. Specialized Apache/Mysql/PHP just to name a few. I would be very leary of trying to install something as major as VPS software on a server thats already functioning with your control panel.
As far as being able to manage the VPS accounts without a control panel. It all depends on how good with UNIX you are, but more importantly how much work you want to do for your customers. If you have no control panel and they're unfamiliar with UNIX you may find you have to do everything by hand for them, which can be very time consuming.
Let's will see...
Can I Re-Install OS; then install some VPS Cp(WHICH IS THE BEST Open source ) Partitioned HDD on part which will be for shared and reseller=inside that re-install Ensim and Modernbill. Rest HDD partitioned for VPS's=Allocated DDR RAM and shared CPU?
Maybe Box will be unstable with shared CPU I mean that allocated RAM will cover all VPS's; Q's is what will be with shared dual-CPU...
Can you re-install Os? No. Not on most. Certainly not recompile the kernel on any of them.
On many UML servers...you can chose what core you want but you certainly cannot reinstall the OS.
I think you're getting confused...a control panel has nothing to do with the type of VPS. A host could offer Plesk and Cpanel on a UML server just as easily as they could offer webmin, direct admin or whatever.
It depends on the host. As was said...you have to be careful with all the dependencies that exist...if you get a VPS with..say..Cpanel and you want to "delete" Cpanel (likely not possible) and install Webmin. The VPS will have to be "remade" or re-installed to do it right.
One of the nice things about the Virtuosso VPS's I have at Steadfastnetworks.com, if I do success in really messing something up...I can reinstall the VPS myself from the Power panel. This is the first host I've had that has this feature and root access as well...and I think it's going to be really ideal for the development work I'm doing.
You have no control of partitions. Most VPS's are very stable...freeVPS suffers from the same "problem" as a shared environment...the CPU resource is not fully allocated. So...depending on how you look at it...if you need to take more than your fair share of the CPU...you can. For the other users...that might be considered to be a bad thing.
VPS's are great for development work and a good, cheaper alternative to a dedicated box to ltruly learn linux sysadmin skills.
with a VPS from ServeSout at www.servesouth, we can make copies of your VPS at any time and then crank out clones of it in just minutes at absolutely no charge. To my knowledge, you can't reinstall your own VPS without the administration of the VPS host..am I wrong guys?