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Best Practices For Infrastructure Upgrade?
An anonymous reader writes "I was put in charge of an aging IT infrastructure that needs a serious overhaul. Current services include the usual suspects, i.e. www, ftp, email, dns, firewall, DHCP — and some more. In most cases, each service runs on its own hardware, some of them for the last seven years straight. The machines still can (mostly) handle the load that ~150 people in multiple offices put on them, but there's hardly any fallback if any of the services die or an office is disconnected. Now, as the hardware must be replaced, I'd like to buff things up a bit: distributed instances of services (at least one instance per office) and a fallback/load-balancing scheme (either to an instance in another office or a duplicated one within the same). Services running on virtualized servers hosted by a single reasonably-sized machine per office (plus one for testing and a spare) seem to recommend themselves. What's you experience with virtualization of services and implementing fallback/load-balancing schemes? What's Best Practice for an update like this? I'm interested in your success stories and anecdotes, but also pointers and (book) references. Thanks!"
The low-budget solution: buy one server (like a Poweredge 2970) with like 16GB RAM, a combination of 15k and 7.2k RAID1 arrays, and 4hr support. Install a free hypervisor like Vmware Server or Xen, and P2V your oldest hardware onto it. Later on you can spend $$$$$ on clustering, HA, SANs, and clouds. But P2V of your old hardware onto new hardware is a cost-effective way to start.
I, personally, am TOTALLY in agreement with the ethos of whoever designed it, a single box for each service.
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Virtualisation is, IMHO, *totally* inappropriate for 99% of cases where it is used, ditto *cloud* computing.
I totally disagree.
Look at some of the services he listed: DNS and DHCP.
You literally can't buy a server these days with less than 2 cores, and getting less than 4 is a challenge. That kind of computing power is overkill for such basic services, so it makes perfect sense to partition a single high-powered box to better utilize it. There is no need to give up redundancy either, you can buy two boxes, and have every key services duplicated between them. Buying two boxes per service on the other hand is insane, especially services like DHCP, which in an environment like that might have to respond to a packet once an hour.
Even the other listed services probably cause negligible load. Most web servers sit there at 0.1% load most of the time, ditto with ftp, which tends to see only sporadic use.
I think you'll find that the exact opposite of your quote is true: for 99% of corporate environments where virtualization is used, it is appropriate. In fact, it's under-used. Most places could save a lot of money by virtualizing more.
I'm guessing you work for an organization where money grows on trees, and you can 'design' whatever the hell you want, and you get the budget for it, no matter how wasteful, right?
Get real, for 150 users at WRT54 will do DNS etc....
Want a bit more poke, VIA EPIA + small flash disk.
"buy a server".. jeez, you work for IBM sales dept?
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If the current system has been acceptable for 7 years, I'm guessing the users needs aren't something so mindbogglingly critical that risk must be removed at any cost. Equally, if that was the case, the business would be either bringing in an experienced team or writing a blank cheque to an external party, not giving it to the guy who changes passwords and has spent the last week putting together a jigsaw of every enterprise option out there, and getting an "n+1" tattoo inside his eyelids.
Finally, 7 years isn't exactly old. We've got a subsidiary company of just that size (150 users, 10 branches) running on Proliant 1600/2500/5500 gear (ie 90's) which we consider capable for the job, which includes Oracle 8, Citrix MF plus a dozen or so more apps and users on current hardware. We have the occasional hardware fault which a maintenance provider can address same day, bill us at ad-hoc rates yet we still see only a couple of thousand dollars a year in maintenance leaving us content that this old junk is still appropriate no matter which we we look at it.
Only big ligs use sigs.
I think what the article is really asking is what's a good model to start all this stuff. You're looking at one or two servers per location (or maybe even network appliances at remote sites).
I totally agree with your premise. In my experience taking something that appears to work (when you realize you've really just been lucky) requires some time to bring about the change that the business really needs.
Now, as for having two servers per location, that heavily depends on how those sites are connected. Are they using a dedicated line or a VPN? That's important since that'll affect what hardware needs to be located where. It's possible (even if unlikely) that some sites would only need a VPN appliance... But since the poster seems to want general advice:
VMWare ESXi is a pretty good starting place for getting going on virtualization. I've had a great experience with it for testing. When you feel like you've got a good handle, get the ESX licenses.
If SAN isn't in your budget, I still recommend some sort of external storage for the critical stuff... Preferably replicated to another site... But you can run the OS on local storage, especially in the early stages. But you'll need to get everything onto external storage to implement the VMotion services and instant failover. Get a good feel for P2V conversion. It'll save you tons of time when it works... It doesn't always, but that's why you'll always test, test and test.
As for the basic services you stated above (www, ftp, email, dns, firewall, dhcp):
Firewall (IMHO) is best done on appliance. Which should be anywhere you have an internet connection coming in. I'm sure you knew that already, but I'm trying to be thorough.
Email is usually going to be on its own instance (guest, cluster, whatever)... But I find that including it in the virtualization strategy has been quite alright. In fact, my experience with virtualization has been quite good except when there is a specific hardware requirement for an application (a custom card, or something like that). USB has been much less of a headcache since VMWare has support for it now, but there are also network based USB adapters (example: USBAnywhere) that provide a port for guest OSes in case you don't use VMWare.