I have 21 wordpress websites in VPS and when apache is restarted, memory always remains less than 500MB (I have 2GB RAM total). But once I access all the websites it goes to around 1GB.
My problem is not going to 1GB RAM when accessed but it never comes back to 500MB after few minutes.
So I had to use a apahe and mysql restart cron job. Do you have any other alternative to avoid apache restart?
It probably goes up due to Apache/PHP processes caching stuff and/or being started only upon first access to a site. I don’t think it’s a bad thing, since all subsequent accesses will be faster. Is there a particular reason why you want to keep memory consumption at 500 MB?