Pros + cons of multiple domains on 1 hosting plan

Hi all,

I am thinking of adding new (top level) domains to my hosting plan on Dreamhost.

I just wondered whether there are any other pros and cons apart from the obvious such as having to share the bandwidth and disk space between the domains? (Which is negligible, considering the quota, anyway!)

Would the different domain names appear effectively separate on the net? Or would there be any kind of association between them? (e.g. same IP.)

Many thanks!


Maybe I’m not the best at this kind of stuff…

but I’m pretty sure there will be no association between the two… but they will share the same IP, but that IP is also shared with the other people on your server so it doesn’t really matter. If you don’t want to share an IP for whatever reason you have you can buy an unique IP from dreamhost.

Get $50 Off all hosting packages with promo code: MADD50 (Sign Up Here)

No cons. The pros are that you can add as many domains as you want with one account.

If you care about IPs, you can also add unique ones for a monthly fee. But it really doesn’t matter. As far as search engines go, being in the same IP range isn’t going to matter unless you’re planning on some sort of SE spam/linking scheme.

:stuck_out_tongue: Save up to $96 at Dreamhost with ALMOST97 promo code (I get $1).
Or save $97 with THEFULL97.

Your own domains won’t necessarily share the same IP. The IPs will be shared, but your account isn’t assigned a specific IP.

There are IPs that have about 10 of my sites on them, then there are others where 1 of mine shares an IP with a bunch of other customers.

I’m glad they do that. It semi-defeats reverse-IP lookups if someone’s trying to find all of your domains. With your average CPanel account, they’ll all be on the same IP.

This is especially good for customers that resell and host others, since it can help keep a competitor from spamming all of your clients.

:stuck_out_tongue: Save up to $96 at Dreamhost with ALMOST97 promo code (I get $1).
Or save $97 with THEFULL97.

Each of the multiple domains is it’s own “entity” on the net, and that fact that they are hosted on a single account woulod not even be apparent to a visitor *they could see that they are both hosted on DH, but not that they are hosted on your single account).

As you correctly deduced, sharing the bandwidth and the disk storage is a bit of a moot point, as the quotas are so generous.

The only other things I think you should consider are the mail and CPU/memory resource quotas (Though there is not longer a “hard” CPU minute quota), which are managed by user.

For this reason, while it might be very convenient to manage all the sites under a single user, I strongly recommend that you set up a seperate user for each domain; that way if one domain has a script run amok, or if the traffic there causes heavier than expected email usage (login confirmations, email update notifications, etc.) you will some extra breathing room, and stand a beter chance of not having all your sites go down because of problems/traffic with a single site.


Hi rlparker,

That sounds like a great idea, but do you suggest assigning a different user name to each domain all within the same single account?



Yes, that is what I am suggesting. It is inconvenient in that you either have to set up some groups/permissions to make it easier for you to manage all the domains or simply log in as the desired user when working on a particular site (which is what I do), but I think it is worth the extra effort.

It keeps the sites nicely segregated and provides the advantages previously mentioned. Additionally, should you decide to delegate some access to the site owner, or another developer, you have not “dropped your pants” completely and displayed all your sites! :slight_smile:


Hi all,

Thanks for all the replies!
Rlparker, when you recommend setting up a separate user for each domain, can you do this within a single hosting account, or do you mean purchasing a separate hosting account for each domain?

Many thanks,


You get up to 75 users even on level 1 accounts, so no reason to buy separate hosting.

$1 for me << [color=#00CC00]SE7ENOF9[/color] | [color=#CC0000]SE7ENOF97[/color] >> All for you

Whenever you create a Fully Hosted Domain, you select the Owner from an existing list of users you created, or a New User. When you select New User, then it’ll prompt you for the typical user account info.


Excellent! Thanks for all the info!

This is actually not true, all of your users will end up on the same machine and if you have a site that is very inefficient and is getting hit all the time by say googlebot or a comment spammer it will affect all of your sites and all of the sites of the other users on the machine.

The only reason we would ever place any limit on a user is to protect the stability of your machine. If you work to try and get around those limitations and tell others to do the same you will only succeed in slightly obscuring the overall problem. I say slightly because your account is a tree structure and we can easily look at usage by user and or account.

If you have free time to do things like trying to spread usage across many users, just use that time to improve the quality and efficiency of your code instead! =)


THANKS! for clearing that up. I apologize for the misinformation and can only claim gross ignorance seasoned with stupidity; I’m not now even sure where I got that idea (and it is bugging me!) :wink:

Please understand that I was specifically told via a support email that email quotas only impacted a given user when I had a script run amok a few years ago. And, in that instance, it was only a single of my users whose mail sending privileges were curtailed for a few hours until I whipped an errant form mailer into submission; the other users on my account were not impacted. Hence, to prevent all my sites from losing their ability to send mail should a single site get exploited, I began establishing new sites as separate users.

This, the email quota, actually, was my main reason for advising this, and I agree that it would be counter-productive to the whole program to use multiple user on the same machine to obfuscate CPU/Memory usage - the machine suffers from over use either way. :wink:

I’m also in complete agreement that there are better ways to use one’s time than managing multiple users in your account, though sometimes it really can’t be avoided if you need to share access to a given domain, due to security concerns.

Hearing now, that all domains hosted under a given account, irrespective of the user, are combined when measuring CPU/Mem usage makes sense, but I am now again concerned about the management of email quotas. I also noticed this morning a recent edit to the DH wiki indicating this is also true with email quotas, and that is really discouraging.

It virtually guarantees that if you host more than a couple of domains that have interactive features (sign-up confirmations, lost password retrieval, new post or message notifications, etc.) you will easily run afoul of the email quota. A a few popular threads or two on a forum where several users wish to be notified of new postings could burn through this quota very quickly; God help you if a digg or /. reference sends a lot users who want to register to your site; when you most need the system to work it is likely to break and prevent them from receiving their “Welcome email” (which in some cases may contain their account information or an activation link).

The same type of traffic could be responsible for numerous “contact form” submissions (many of which are set up to email the site owner and cc the sender). It also pretty much precludes the use of any “tell a friend” interactivity; multiple sites with any traffic would combine to quickly exceed the by account quota. I’m afraid that even a single busy site would not be able to use these email features, and these are all commonly expected features of an interactive site.

If all users/domain etc on an account have their email usage accumulated into the single quota total…hosting multiple site with any degree of user interactivity at all would be become virtually impractical.

I agree with you on CPU/Mem usage, and I guess I must have just made a disconnect somewhere with that information, and am actually glad to have that clarified…I apologize profusely for the misinformation.

That said, can you please confirm/deny or further clarify the way the email quota numbers are accumulated? That is critically important to me, and my clients, and I don’t want to remain confused about this or set my clients up for serious dissatisfaction if this jumps up and bites them! :open_mouth:



rlparker -

Michael pointed me to this thread so that I could provide a little clarification on this stuff…

I’m not sure what the wiki edit is about, but as it is now we look at (and limit) email usage on a per-user basis. I do not know of any plans to lump multiple users all together and institute a throttle limit for them as a whole - and DreamHost Abuse are the ones who would be enforcing those limits, so we’d probably be in on it. :slight_smile:

Regarding the limits in general:

Most people never bump up against those limits, and those who do can contact us, explain their situation/needs, and then potentially have their limit increased. If they are using bulk email in any way we will likely need to independently verify that they are fully compliant with our anti-spam policies before doing so.

That said, this multiple user thing shouldn’t be seen as a loophole. We’ve actually had people try to round-robin their email output through multiple accounts on the same server in order to avoid getting “caught” trying to send large amounts of bulk email. While this will likely work for a bit, eventually we will notice and such abuse will likely result in our tightening things up or adding restrictions for everyone. It’s in everyone’s best interests not to monopolize server resources more than necessary.

And no, its clear that you’re not trying to game the system - I’m mostly mentioning that for anyone who runs into this thread down the road and gets some wild ideas… :slight_smile:

Anyhow, if you have multiple distinct web sites with different mail needs, if you put them all under different user accounts they will be relatively isolated and have their own limits. I recommend doing this anyhow as it limits the potential damage should an insecure script get exploited, a password sniffed, etc. It also lessens the amount of material to sift through and clear when securing such an account.

While there is some benefit to having a bunch of domains under the same login when it comes to convenience, I personally prefer the added security of keeping them separate. To each their own, though!

  • Jeff @ DreamHost Abuse

By default all of your shell users will be in the same group, so some configuration would be needed to have additional security from multiple user permissions.

Thanks so much, Michael, for the clarification. That helps a lot and, actually, is consistent with how I was led to believe (and have actually found) it works. :slight_smile:

I’m glad to see you recognize a legitimate use for those “multiple users” and that you are aware that some may attempt to exploit that to everyone’s detriment. I hope you are able to continue to allow user based quota evaluation (rather than account) AND you are able to identify and deal with abusers without changing that segregation of users for quota purposes.

Outstanding! That is what I was trying to get clarified. I thought I understood it to work that way, but was confused after reading Michael’s post. You also much better described what I was trying to say to the original poster. Thanks!

As you can tell, I feel the same way about this, though I admit I continue to run several domains under a single user which I initially set up that way a long time ago. That said, all my new domains get their own user, and I think I’ll continue to go that route in the future for all the reasons (both quota and security related) you so well stated.

Thanks again for taking the time to set us straight on all this. Rock ON!


Thanks for that! It’s a particularly good point if all the users are full “shell users” as opposed to “ftp only” users.

To the degree that “security” is a somewhat relative term, I still think some additional “security” can be derived by using separate users given the operation of suexec, and I know that, for me, a “bad” script is much easer to locate if different domains run cgi as different users.