Usage of RAM on the Apache server

How much is optimal RAM usage?

[vidya]

We hire a tech support company that tells us, that on our dedicated Linux server, we have "used almost 7700MB of your RAM and you have only less than 300MB RAM available on your server."

Now is that necessarily a bad thing?

Could it be that the server is grabbing all the RAM for caches?

Or is it possible there's something else going on? That we need to adjust?

Yes, I know that's too general a question to answer, but maybe you could point me in the right direction.

Thanks

...Vidya

[jdMorgan]

That would depend on how "peaky" your traffic is, and what level of service you're willing to tolerate for your users when the site is busy.

Personally, I'd want at least a 33% margin above "average" memory use to handle peak-load conditions without a noticeable slow-down in your site's performance under load. But that's a "too-general" answer as well... :)

Having too little RAM available can result in excessive swapping, and cache thrashing as well. 300MB spare over 7700MB used sounds like a paper-thin margin. RAM is (should be) cheap -- stick 2GB in this box and forget about it for awhile.

Jim