2010-03-19 I walked in this morning at work with so ...
I walked in this morning at work with some people looking at me expectingly. About the third person was nice enough to explain: home directories and mail were unavailable. A quick look showed me that the home directory server was waiting for the ldap server and the ldap server showed a kernel panic on the console. Strangely enough the root ldap object was still available so the monitoring system did not notice it.
Anyway, server systems should not wait for the systems administrator after a panic in my opinion, they should be available. So I looked it up, and indeed: Linux Kernel panic reboot explains how simple it is to change this setting. So I changed all servers at work to give up after a panic and reboot. That should help availability. I'm not interested in the intimate details of a panic, I want working ldap. Yes, as several people noted to me, there are ways in which this can lead to a reboot-loop, for example when the panic is file-system related. I'll take that risk when it will 'fix' all other problems.
unix - linux - storage unixfoo is good at linux and netapp knowledge. I browsed it for a while and found lots of interesting stuff.