CentOS vs Debian Install OpenVZ 512 MB RAM

Been trying to get a small VPS up. It is OpenVZ, 512 MB of RAM. No swap allowed.

Debian 5 and 6 installer crashes during virtualmin-base, out of memory.

Centos 5.5 installer stays under 90 MB the whole time.

Why do you feel this happens?


Do you know how much of that RAM is “dedicated” RAM? If the system requests RAM, but it’s not available, that can cause some strange problems.

If you keep getting out of memory errors though, it’s probably just that… either the system attempted to allocate more than that 512MB of RAM and it wasn’t able to, or that 512MB isn’t dedicated RAM, and what ever amount is dedicated, you ran out of.

Either which way – you’ll likely need more dedicated RAM in your VPS :slight_smile:


Actually, this here explains the problem pretty well:


I was having a similar issue and was pulling my hair out on IRC. I expect that Debian pulls down more things eating more RAM than CentOS does. My frustration level got too high, so I am not up to investigating further.

Note that just doing simple-ish things on a base Debian install on a 512MB VPS will often cause large memory spikes, as well.

But yeah, it looks like something where the ball’s really in Debian’s court here, not Virtualmin’s. I guess the answer is “CentOS on resource-constrained systems”.

@lewellyn: I believe that CentOS is the ticket for low memory VPS. Got the sites moved to it and where Debian used over 400 megs under normal load (even with clam/spam disabled) CentOS is using less than 300 megs of RAM.

The host is 256/512, but I run top in a separate window and the installer crash always happens at 480+.

I think their (Debian’s) package installation system is just broken, in terms of sanely allocating memory. :frowning:

Luckily, Virtualmin helps to abstract the underlying distro out a bit, so as long as something works, it’s consistent. :slight_smile:

And I’m glad to hear that I’m not the only one who found some love in CentOS on an OpenVZ VPS. :slight_smile:

Been using strictly Debian since the late 90’s, always avoided Redhat distros.

Since CentOS 5.6 just came out, this seems like a good time to learn Redhat.