I have been client of OVH for years now, and I never was disappointed: they won’t sell you the moon (for instance, cheap crappy servers), but you get what you paid for, including a very good support. However, with time I discovered some issues that might be noteworthy to mention.
EDIT: I posted an update to this post.
Installing the server
The first thing you get to do with your server is to install an OS. Here you usually choose whatever you prefer. If in doubt, choose Debian, since it is the best OS ever you can’t be deceived by it, but you are free to have bad tastes. Ahem. Whatever, there is a golden rule here: do not ever under any pretext choose the “OVH Release 2″. Never ever. It’s kinda a transgenic Gentoo, so heavily modified that you can’t do anything on it. In short, the only way to administrate it is to use the embedded Webmin. And forget about updates. Urgh.
If I recall correctly, when you install your server for the first time, you don’t have much choice about partitioning. Or maybe is it because I did that long ago ? Anyway, if you want custom partitioning, in the worst case you can do it by re-installing the server, the process is quite fast and straightforward. However as far as I am concerned, I find the web interface a bit too restricted regarding LVM configuration, so I generally simply install a standard OVH Debian, create my LVM layout, and debootstrap the thing.
Kernel Updates
There is something else that I find embarrassing, it’s the fact that the kernel is supposed to be loaded by netboot. Their rationale is this: they give you an always up-to-date kernel patched with grsecurity. Why not, this should help you not worrying about the kernel. But in fact, you don’t want the last kernel, you just want a secure kernel. Indeed, you can achieve this by using the OVH kernel, but that would imply to reboot each time there’s a new version out, because you can’t really sort out which versions include a security fix, and which ones do not.
What I prefer to do instead, it’s to install a standard Debian kernel, and read debian-security-announces. This way I only have to reboot when my kernel is flawed.
Server Monitoring
OVH is able to perform some basic monitoring on your server, which can be useful, but to some extent might lead you to serious troubles. Not that monitoring is bad, but by default if your server do not ping for 5 minutes or so, it will automatically be rebooted into rescue mode. Big mistake. Because the day when your server will go through a long fsck while booting, it will never be able to start and it might take you a long time to figure out why (true story, and remember you don’t see the screen).
What I always do is to disable this auto-reboot, and do manual reboots when needed. It won’t cause longer downtime, because the auto-reboot puts the server in rescue mode, and then no services are served. There’s quite fewer disadvantages to manually reboot the server. But of course, it’s also up to you to decide of an action plan to detect when your server(s) go down and what to do then.
Rescue Mode
Talking about rescue mode, what is it? It’s a special kernel/distro you can boot through your manager, that embeds a web interface and some basic tools to help you repair your server in case of problems. This is a very, very useful feature! Nothing bad to mention about it, just wanted to bring it up in case you wouldn’t know it.
Oh I’ll forgot. There is a slight problem with it, actually. When you reboot into rescue mode, the root password will be mailed to you. It is fine, but the mail might take quite a while to reach its destination (anywhere between 5 and 20 minutes).
Backup
I think that nowdays, each and every OVH server comes with at least 100Gio of FTP backup. This is really great, but their FTP is quite paranoid and limited. Not that I don’t understand the reasons behind this, but this means that you’ll have to deal with it. A few years ago, I created a script based on incremental tar snapshots to do the job, but recently I discovered duplicity, who fills the duty pretty well and is quite simple to use.
Support
OVH support is great: they are not just reading procedures, they know what they talk about. And when you have a hardware problem, you won’t have any trouble to get it changed. For instance, I had a flawed hard drive, and after a simple email showing a SMART report, I had the replacement planned. And they kept the old drive connected, so I could copy the data. I also had several issues of failing power, which were well detected and immediately replaced. Big up for OVH support !
One dark point however: the phone support is just awful. Not because of the people behind it, but because of the utterly atrocious music (seriously, did anyone tell the people making hotlines about Shannon’s Theorem? You CAN’T put high-pitched music on the phone), and because of the long waiting. If you want something done, just use the email support, it will save you a lot of time and money and headaches.
Mail history
The OVH manager is quite a piece of software, with a lot of surprises awaiting you. While I seriously doubt the mental sanity of people coding this stuff, you can’t avoid it to administrate your server and associated services. There is a quite unknown and half-hidden feature that however can be very useful: the emails history. You can find the whole history of emails that OVH sent to you. Including sometimes those that you did not receive (yet). Might boost the time to access the Rescue Mode (or not).
To access it, in French: from the Manager v3, go to “Administration”, “Mes paramètres” and then choose “Historique des emails”. I don’t know the English translation, probably “Administration” -> “My parameters” -> “History of emails”.
Conclusion
Of course, everything isn’t nice and shiny, but I never had any serious problem with OVH on the areas that matter. Whatever people say, the network is quite good, there is IPv6, I never had a power outage, and the support is just fine. I clearly won’t recommend OVH for specific applications, say e-commerce, but for general purpose hosting with a good overall quality of service, I’m quite satisfied, once I’ve applied my little workarounds. I have been around for at least 4 years, and I am still alive :)