I've been looking at the fetchers via terminal and sometimes see a message saying "could not resolve host: somewebsite.com" What does this mean?

-- Could not resolve host

It likely means the DNS lookup of the host failed. This can be because there is no such host, or it can be because the DNS server took too long to respond. Best, Chris

-- Could not resolve host

Made a sample crawl of 30 links it worked. Afterwards Fetcher shows error in terminal. 1) mmap(): memory not allocated 2) could not resolve host xyz.com nsdefine() in config.php needs to be modified or leave it as =000M default. Not understanding really