I'm considering hosting our web servers, etc on linode. Mostly positive reviews from what I have read.

I wonder though if a VPS is good for a sql/nosql database? I would rather purchase database space hosted/managed on a physical server tuned for I/O performance.

The combination of VPS for web and application servers communicating w/ PostgreSQL, MySQL or MongoDB on physical servers would be ideal.

You could rent a physical server from one of the datacenters where your linodes are located, e.g. The Planet. Then the latency between your physical and virtual servers will be negligible

Seriously, though, you'd want your database (or at least the indexes + active portion of tables) to fit in RAM. Compare the cost of a large linode with lots of RAM (e.g. linode 5760) with a physical server with all the necessary I/O optimizations such as SAS drives in RAID 10.

I was thinking more of a hybrid solution offered by linode. The database is almost always the bottleneck of most web applications. If Linode offered database resources deployed on physical servers, they would surely outperform any virtualized database.

Linode could price a database resource just like a node. A 1440 database would guarantee that only 10 accounts could access that server. Seems like a win-win to me. I don't know of any hosting that provides a combination of services like this.

We can't make unquantified claims like this, nor can we tell you based on what don't know about your needs that it will or won't work. There are plenty of resources to go around, but an untuned app is going to run like crap on real hardware or on a VPS. Tuning is critical. So, my advice: try it and see, and then tune it

-Chris

A friend once told me, "if it aint broke, tweak it. if it is broke, more duct tape"

It has become words to live by.

_________________
If it ain't broke, you didn't tweak it enough. If it is broke, use more duct tape.
http://independentchaos.com

The difference in performance between a Xen virtualised environment and a native environment is rarely worse than a few percentage points.

If "the database is almost always the bottleneck of most web applications", having a physical server of just databases all thrashing I/O certainly wouldn't offer better performance than a VPS where you'll be sharing resources with users who may not need as much disk I/O.