Thread: To VPS or not to VPS?

Hi Guys, Great discussion here. What in your opinion is oversold? I mean how many VPS on one server is considered oversold? Thanks for your input (still learning) Take Care, Michael Silvester

Quote: Originally Posted by citycm I asked my provider if they oversell CPU/Ram and they just said 'Nope we do not oversell any resources'. It took some pushing but they then told me they have 15-20 VPS's per server. I don't think any provider will say they are overselling! why not give them a try for a month and see for yourself then post a review here. cheers, Roel

When the admin creates a VPS, they specify the number of CPU cores, RAM, and disk space to allocate to the VPS. Add those up and add to the totals what is needed by the hypervisor. If any one of those totals (CPU cores, RAM, or disk space) exceed what is physically in the machine, it is oversold. Apparently, I take a much more conservative view than other people.

Even trying to strictly define overselling can be difficult - RAM on OpenVZ is very blurry and disk i/o can be an issue on any system (eg. imagine 20 VPSs given 50GB disk space each on a server with a single 1TB SATA drive). The key point here is: if you seem to be getting more than your money's worth, look for a reason!

Unfortunately, there are many providers that oversell and try to hide it. Just like any industry, there are always people that will overpromise and under-deliver.

Thanks Neil, Is there a test that I can do to check performance or overselling before I commit to a hosting provider? Take Care, Michael Silvester

Quote: Originally Posted by citycm I asked my provider if they oversell CPU/Ram and they just said 'Nope we do not oversell any resources'. It took some pushing but they then told me they have 15-20 VPS's per server. I don't think any provider will say they are overselling! why not give them a try for a month and see for yourself then post a review here. cheers, Roel

Even trying to strictly define overselling can be difficult - RAM on OpenVZ is very blurry and disk i/o can be an issue on any system (eg. imagine 20 VPSs given 50GB disk space each on a server with a single 1TB SATA drive). The key point here is: if you seem to be getting more than your money's worth, look for a reason!

Hi! Oversold, in my understanding: + RAM: Add all VPSs memory (in case of OpenVZ/Virtuozzo, maximum memory). If this is > physical RAM, you can say that RAM is being oversold. This is not a big issue, as long as the "overselling" isn't huge (I would say that, with OpenVZ, you can oversell up to 10% over your physical RAM with no issues). + CPU: this is harder to come by, it will depend on the apps that run on...

I agree with the post above, main issues we have seen are CPU ready time. We stick to a a maximum limit of 4 vm's per core which works well in a vmware environment disk io could be an issue, worth asking what cache the raid cards have and are they using battery backed write cache