OK, a simple google search defined zebra for me, but second question still applies - how do know if it's running?


To know whether zebra is running: do:

ps -ef | grep zebrasrv

It should return something like:
marty@debian:~$ ps -ef | grep zebrasrv
koha      3281     1  0 20:39 ?        00:00:00 daemon --name=koha-zebra-ctl.koha --errlog=/var/log/koha/koha-zebradaemon.err --stdout=/var/log/koha/koha-zebradaemon.log --output=/var/log/koha/koha-zebradaemon-output.log --verbose=1 --respawn --delay=30 --user=koha koha -- /usr/bin/zebrasrv -v none,fatal,warn -f /etc/koha/koha-conf.xml
koha      3282  3281  4 20:39 ?        00:00:00 /usr/bin/zebrasrv -v none,fatal,warn -f /etc/koha/koha-conf.xml
marty     3284  3244  0 20:39 pts/0    00:00:00 grep zebrasrv

( To compare: if it is not running you will get something like this:
marty@debian:~$ ps -ef | grep zebrasrv
marty     3274  3244  0 20:34 pts/0    00:00:00 grep zebrasrv )