vDevices
If you search these forums on posts by RequestedDeletion (use the forum search filters), you should find references in approximately the last year or so to a VFS install from iso at a hosting company.
Hsing Foo (RequestedDeletion) got the host company to upload the sme iso & make it available for installation to a VFS, so search & try that option rather than DO.
If DO will not make the iso available for install, then there is not much you can do with them
Alternatively, & this is a very different approach that requires a sme server install to start with, is this Howto.
http://wiki.contribs.org/Thinclient_usageI have not tried it, but it appears that you can make the sme server iso (& other distros) available to the network for (compatible) workstations to boot up to.
Really if you went to that trouble, you would just install sme server from CD on any old workstation you have for testing.
I have sme8 & sme 9 running adequately (albeit slowly), on some old Celeron 500MHz PC's with 256K RAM, a joke I know, but it works.
Once you start using sme you will be even more impressed, & when you get into using custom templates you will be even more impresssed. Then when you start to install the myriad of contribs available, you will be impressed even further.
Then finally in maybe a few months when sme9 final is released, you will really be impressed.
Although sme9 beta2/3 is already available & impressive.
It would be very hard &/or a lot of work putting sme on top of a CentOS install, but essentially that is what sme server already is.
There were some references to Scientific Linux & installing sme on that in these forums, I recall that post led to a few other things too which are very informative re how to do what you want, so again do some searching on that distro name in these forums & I think that was posted by RequestedDeletion also, about a year or so ago (??).
As far as virtual installs goes, you could setup a virtual server using Proxmox or one of many others on an existing machine, then add sme as a virtual install. It's not on the net but that may achieve what you want for test purposes. Search these forums for currently recommended virtual software that are the "better" ones to use.
Also early in 2013, development work for sme 9 suddenly started, & there was a plethora of details about how to get sme onto a CentOS 6 minimal install, so that sme 8 functionality could start to be tested when running on a CentOS 6 base. I think a lot of that is in the devinfo & perhaps the discussion mailing lists archives & in contribs.org bugzilla, so if you search there also & read the many posts that were being made, that would be very likely to give you ideas & details re how to do it. Really you are just recreating sme server, so it seems pointless to me, & an awfully complicated approach just to avoid installing from a CD or iso so you can test sme server.
Just grab any old (physical) workstation or server that is compatible with Linux RHEL & CentOS 5/6 & install sme from CD onto it for test purposes.