'core' files in Solaris

Lately, I've been getting messages saying:

NOTICE: alloc: /: file system full

so I'm trying to clear some disk space on my root partition. I've found some messages in the Sun forums reccommending deleting files named 'core', but nothing telling me what these files are. I'm a little reluctant to delete these files as they are owned by root, and I don't know if they are necessary or not. Can anyone tell me more about these:

/usr/lib/.../core
/etc/named/core
/core

This is the same system I was talking about in my last post, and the guy who set it up put /var on the root partition so it has a tendency to fill up quickly.

Thanks

--- Cerbere

core files are basically memory snapshots from when a program segfaults (segmentation fault, like walking past the end of an allocated array). If you aren't going to use them, delete them, as they don't serve any purpose other than to help debug why a program crashed. This is a one-liner to find all files named "core" on the system and delete them, though take care in doing so as not all files named "core" are necessarily core dumps:

find / -name core -type -f | xargs rm -f

Untested, but it should work (for every mounted filesystem)