I just moved to a new VPS which on paper is better than my old VPS - faster processor, more RAM, more bandwidth, etc. - but I have just discovered it all means nothing.

Apparently the only thing that really matters is how much kernel memory you are allotted when they set up the VPS and I assume that is dependent on how many VPS's are on the server.

So, my new VPS gives me slightly less memory than my old - which is causing hpptd to crash - even with this light weekend traffic. I am going to hate to see what happens after this long weekend!

Any ideas as to what I can change to reduce this memory usage - which incidentally seems to be high even when the forums are closed?

Something doesn't seem right as it seems from the memory being used that I need a dedicated server and not a VPS just to run the BB.

Are you getting CPU exceeded pages and such on your site?

I have seen this with many hosting companies causing many interactive sites to be CPU limited and causing outages on the site.

I am not really sure what you are asking as I really do not know much about the technical end

Right now though, with about half the normal traffic I receive "server load" is flashing red at "2.19" so another crash is imminent by the looks of things.

I might have jumped to some false conclusions about the memory limits and was reading some numbers wrong. The culprit may be statistics software running in the background. I have limited when they can run now so I will have to monitor this I guess.

You may need to tune apache to work properly on the new server; it's usually configured (by default) to have ultimately unlimited resources

You have'nt written one of your excellent FAQs on the subject by any chance have you?

I was searching the net for one and keep finding links to one that sounds excellent - but the site no longer exists...

Well, it can honestly vary, and a lot of it can be just trial and error... We have 384mb ram allocated, so our config is tuned low:

Thanks Gizmo, that gives me a starting point.

I am using WHM and they have a link there for Memory Restrictions - "This tool will calculate new Apache memory limits based upon past memory usage. The new memory limits will be updated in the Apache configuration."

I don't know if using this would be a good thing or a bad thing - does anyone have any experience with this tool? If I am crashing because of lack of memory it seems to me using a "Memory Restriction" tool may not be what I am looking for...

Personally, I find these CP's everyone uses for small setups overkill... they use a lot of resources lol.. you probably run under 20 sites on your vps? I run over 50, and just use WebMin/VirtualMin, which leave a tiny footprint on the server.

Gizmo, you have MaxRequestsPerChild 8000
I have MaxRequestsPerChild 0 - zero, diddly - can't be good, can it?

I guess O actually means "unlimited" so not a problem perhaps.

I was about to post this:


Till I saw your other reply lol...

Not sure how it'll work with 0, I think it'll just keep the apache proces alive all the time vs killing it; so if you spawn too many child processes they'll all remain, which could actually be bad...

Just the one site on this server- the forum. I chose cpanel because I am more familiar with it than I am with others - and it helps with my command-line-avoidance

About the MaxRequestsPerChild - from what I was reading last night, putting a limit on the setting only is needed on a few certain servers - Solaris being mentioned if I recall correctly.

Last night I relaized that I could also check the "use persistent connections" box in the forum control panel - which would control the numbers of childs to some degree (if I understand the concept correctly) and aso reduce CPU usage to some degree I believe.

Lol, please do yourself a favor, do not ever click that option (persistent connections) unless you own the server and have several gigs of ram available...

Sounds like you are speaking from experience on that - unchecking the box as I type....

So today it was mysql that crashed - not apache. A pattern has developed - the server's bandwidth statistics script runs every 6 hours and drives my server load up from the .5 to .9 range to the 2.4 or higher "red" range - which this afternoon resulted in the database crash.

I can't seem to find a way to change when the bandwidth stats are run - or to turn them off. I have contacted support - they must be getting tired of me by now

I guess this statement really was correct. I have been having problems because I keep reaching my kmemsize limit - which, it turns out is only a fraction of what I had on the old server - even though the new server's advertised specs are much better. No one advertises "kmemsize".

Perhaps the support people don't even know what it is as they keep saying kmemsize is a result of not enough ram and I need more ram (already have 50% more than on the old server).

A quick search on Google says that kmemsize is "the size of unswappable kernel memory allocated for the internal kernel structures for the processes of a particular VPS."

That does not sound like ram to me.

So, before signing up for any hosting I suggest asking about kmemsize.

Overnight I moved back to my old server (with more kmemsize) and this morning support at the new server finally got around to answering my question - confirming that all of their plans have the same kmemsize - so if you buy the top of the line plan your forum will run no better than if you opt for the cheapest - as the weak link in the chain is kmemsize - and that information is not available on hosting companies websites....

you could move to my dedicated server box and not worry about kmemsize

I am going to have to do something as moving back to my old host is just temporary. I am going to let things settle for a couple of weeks (hopefully) and let members forget about the recent disruptions before actually moving again.

I do want to move though as I have no confidence in my current host and I would like to have an uneventful summer spent fishing, golfing, and traveling - not worrying about whether the forums are up and running.

Perhaps you could PM me some info Sirdude?