Installing WordPress Multisite

I would like to install multisite on WP, I tried to put

define(’WP_ALLOW_MULTISITE’, true);

in the wp-config.php but its not working

 

You have to follow ALL of the steps.
http://codex.wordpress.org/Create_A_Network ( scroll down to Step 2)

If you are trying to run it on subdomains and you are on shared hosting, you have to make sure your host even allows it, if they do, you need to have them set the wildcard so that sites on subdomains can be created.

You should be able to run in on folders with no problem.

I HIGHLY recommend Dedicated Server hosting for a multisite network. I can't say it enough times. Running a multisite on shared hosting SUCKS. It nor it's plug ins do not run well on shared hosting.

 

I was just about to install it on a shared host, and that is a serious network blog project I had in mind. Why would it suck using sharing hosting? Dedicated host is a bit pricey. I will be using it for a few blogs connected in a network. Blogs will be closed for subscribers, so only about 10 blog sites will be in play. Do you still think it will be bad? if yes, what problems should I be expecting ?

 

Shared hosting is fine if you are running 1 or 2 sites, and even then depending on the company it can still be slow. Shared hosting is cramming multiple sites on the same server, most with the same IP address. Most shared hosting providers barely have the resources to run multiple WordPress sites with all of their plug ins and amateur webmasters messing around with the coding. So you are basically at the mercy of not just the resources of the company but the other sites on the server.

So now you want to put a "Serious network project" on there? With 10 blogs? Technically, unless the host has prevented it, you can do the installation. That's not the issue. The issue is that most shared hosting providers, ( Especially Go Daddy) are already strained to their max.

Not only that, but you won't be able to apply any custom features like private domains or each site, instead of subdomains or folders ( because that requires at least a dedicated IP).

You also have to understand that most Network or BuddyPress plug in developers, don't usually take shared hosting into account or test them on shared hosting because it is not recommended to run a network on shared hosting.

So what problems can you expect?

You can expect it to be slow. Plain and simple. You may increase some speed by keeping plug ins to a minimum, getting a dedicated IP address and using a cache plug in, but you need to discuss with your host. It's unfair to just throw up a network on shared hosting which has limited resources and then expect them to deliver the resources to run it. That's a lot to ask for $7 a month.

Also, some shared hosts don't allow wildcard domains.

Of course Dedicated Hosting is a bit pricey. No one ever said that this was a cheap business. When you want to do more stuff, you have to pay for the resources to back it up.

But honestly, it depends on your host and the amount of resources your network uses. If you are with a quality company that doesn't cram as many sites as possible on every server, you may be totally fine, especially if your network doesn't get a lot of traffic.
If you are with Go Daddy. I don't recommend it.

 

You won't know for sure until you try it, or talk to your host.

I learned the lesson a long time and now will never use shared hosting ever again.
I also use a dedicated IP address for every site.

I understand the economics of it, but if you are going to start getting into Networks, you should make those 2 things a goal for the future.

 

I'm with imageleet for several years and I have about 10 blogs of which few are constant and more serious. I have never had any problems with speed or anything else whatsoever. I know dedicated server is far better, but up until now I never had the need nor the budget to put these on a dedicated.

However, I have successfully installed a sample of Wordpress MultiSite for testing purposes on my shared hosting account, and so far so good. Haven't had any problem, but still I'm only testing with basic features so in future problems may arise with plugins as you suggested. By the way, I have installed the domain mapping plugin and successfully configured a few blogs on private domains (not subdomains). Actually the setup was a breeze. So I guess I will be starting out with a shared at imageleet for now, and if things get complicated move out to a virtual or dedicated.

They don't seem like they are overselling or crowded because I have ran download/mirror sites (again not so big)

 

That's all you can do. Test it, try it out, and if you see that it's going to need more resources than you can make a decision from there.
Sounds like you have a decent host, and if the speed is fine, you may be able to get away with a low traffic network for a while until you need to spend more.