I used 1and1 for a project a few years ago. I would say that it works OK in a shared hosting environment. We had some speed issues, but that had more to do with caching then shared hosting. The client already had the hosting and it wouldn't have been my first choice.

That site is on 5.6 and I can't vouch for 5.7.

appsforinvestigators.com

I used 1and1 for a project a few years ago

We are trying to update our systems to php 7.2

We have 'switched on' php 7.2 on oursystem

However our system is not working properly because pdo mysql_connect
function and some other functions of php like eregi are not found.
mysql_connect is very basic function .

Could you tell me how or where I can get other functions such as pdo and
eregi installed on the managed server, to get php7.2 to work?

On 1&1 shared hosting a lot depends on who the site is sharing with. Sometimes you can be very unlucky.

If the existing site preforms well and you are on the same server, then the new c5 site probably will also. However, for a live site c5 should ideally be on a linux server, not an MS server.

The main difficulty I find with 1&1 is they have their own control panel rather than the usual cPanel that most hosts provide. In some ways its better. In other ways its awkward, and its overall just different.

Agree on the cPanel thing. Awkward.

I know that 1and1 offers Linux hosting so I guess that should not be a problem, at least that is what their technical support has told me.
My personal web site where I use concrete 5 is limited on 20 meg file size that I can upload so that others may download. And I don't know if that is a function of Concrete or the webhost which I think is ENOM, but can't be sure since I actually paid a third party to set it up earlier this year. Plus when the website quit working for no reason I had to pay the third party a couple of hundred bucks to fix it so I gotta get out of that trap ASAP.
Also webspace seems to be limited using ENOM as a host. I almost out of webspace, versus 1and1 where there is oodles comparitivly.
Again Thanks for your assistance and comments.

I set up some client sites on 1&1 and they are running well, but as John pointed out, you can be unlucky with your Neighbours on the shared disc.

I've had good experiences with 1&1 tech support so far and the dashboard is a little chaotic to me, you just need to click your way through some pages to find everything. But I havent experiencend anything that would make me say "stay away from 1&1".

I used 1and1 for a project a few years ago

We are trying to update our systems to php 7.2

We have 'switched on' php 7.2 on oursystem

However our system is not working properly because pdo mysql_connect
function and some other functions of php like eregi are not found.
mysql_connect is very basic function .

Could you tell me how or where I can get other functions such as pdo and
eregi installed on the managed server, to get php7.2 to work?

What version of concrete are you using?