Cheapest way to combine 18 Linux servers into one (or two)

[CougTek]

I've calculated that we have 18 servers running on various Linux distributions. I'm trying to find a way to combine their functions into a single server and then duplicate it on a second one, purely for redundancy. Yes, a single, very powerful server, could be enough, performance-wise, to do all the 18-servers' jobs. My problem lies with the cost of the software to accomplish this.

I imagine there's no way to only use a free VM manager like Xen Server or ESXi to run 18 different VM? With ESXi, I'd need to buy an expensive vSphere license. The server hosting all the VMs would be a 2-socket one (well, two times 2-socket because of the backup server).

I've also thought about separating each application in Linux Jails. I have zero experience doing this on Linux, but I'm reasonnably good at doing it in OpenIndiana. I assume, probably wrongly, that it works similarly.

Overall, we have 26 servers with Windows operating systems, 26 with Solaris-derivative, 3 with BSD and the remaining 18 with Linux. I plan to run everything on a 12-servers setup. The 26 Solaris and 26 Windows OS servers, I've found a way to compress them. I'm now trying to find a solution for the BSD and Linux servers.

 

[ddrueding]

IIRC, the limitations on the free version of ESXi were on CPU sockets. I think two is allowed, and as many VMs as you want to put on there is fine. With this approach, you can just do a Physical->Virtual conversion and move all 18 as-is onto a single machine.

 

[Chewy509]

If you can consolidate the Linux distributions to the few that offer full support for Xen, then Xen would be my recommendation. IIRC NetBSD and FreeBSD both support running as Xen guests, so that would allow you to consolidation both OSes onto the same hardware... (You can also run Windows on top of Xen as well, if you have enough time/patience to do so).

Plus, Xen is cost free as long as you're willing to deal with the administrations tools that come natively with Xen.

AFAIK The best "Jails" offering on Linux is OpenVZ, but have never used it, so cannot offer any real suggestions for or against it.

PS. http://wiki.xen.org/wiki/Getting_Started

 

[Mercutio]

I'm almost positive that ESXi is limited to only one physical CPU of up to six real cores. That's how I read the license agreement anyway.

Xen seems relatively straightforward and it's already baked in to some *nix systems.

The thing that still gives me pause with all the available hypervisors is how scary and hack-ish the backup systems are for anything less than enterprise-grade licensing.

 

[ddrueding]

The thing that still gives me pause with all the available hypervisors is how scary and hack-ish the backup systems are for anything less than enterprise-grade licensing.

This. I'm about to implement some kind of in-VM disk imaging tool just cause the rest is scary.

 

[Howell]

Esxi 5 is not limited by CPUs at all. It is limited at 32G per physical box. With enough physical boxes you do what you need to do. IMO you need to develop a backup plan even before you develop a failover plan. Start with the RTO basics.

Although I have previous experience with Citrix XenServer my most recent experience is with ESX so that's what I would go with. Managing multiple boxes with vsphere is dead simple.