# zgrep 'zkt' syslog.1.gz
May 29 05:00:01 services zkt-signer: notice: ------------------------------------------------------------
May 29 05:00:01 services zkt-signer: notice: running /usr/bin/zkt-signer -v -v 
May 29 05:00:01 services zkt-signer: notice: "2.17.172.in-addr.arpa.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: notice: "176-29.236.154.213.in-addr.arpa.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: notice: "0.0.0.0.e.f.2.0.8.b.7.0.1.0.0.2.ip6.arpa.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: notice: "dmz.freshdot.net.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: notice: "vm.freshdot.net.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: error: zone "vm.freshdot.net.": couldn't increment serialno in file /etc/bind/master/net/freshdot.net/vm.freshdot.net/zone.db: no serial number found in zone file
May 29 05:00:01 services zkt-signer: notice: "freshdot.net.": re-signing triggered: Modified KSK in delegated domain
May 29 05:00:01 services zkt-signer: error: zone "freshdot.net.": couldn't increment serialno in file /etc/bind/master/net/freshdot.net/zone.db: no serial number found in zone file
May 29 05:00:01 services zkt-signer: notice: "thesmallprint.nl.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: error: zone "thesmallprint.nl.": couldn't increment serialno in file /etc/bind/master/nl/thesmallprint.nl/zone.db: no serial number found in zone file
May 29 05:00:01 services zkt-signer: notice: "freshdot.org.": re-signing triggered: re-signing interval (2w) reached
May 29 05:00:01 services zkt-signer: error: zone "freshdot.org.": couldn't increment serialno in file /etc/bind/master/org/freshdot.org/zone.db: no serial number found in zone file
May 29 05:00:01 services zkt-signer: notice: end of run: 4 errors occured



Tried again in the morning:
# zgrep 'zkt' syslog
May 29 08:43:29 services zkt-signer: notice: ------------------------------------------------------------
May 29 08:43:29 services zkt-signer: notice: running /usr/bin/zkt-signer -v -v -D /etc/bind/master/net freshdot.net. 
May 29 08:43:29 services zkt-signer: notice: "freshdot.net.": re-signing triggered: Modified KSK in delegated domain
May 29 08:43:30 services zkt-signer: notice: end of run: 0 errors occured
May 29 09:14:27 services zkt-signer: notice: ------------------------------------------------------------
May 29 09:14:27 services zkt-signer: notice: running /usr/bin/zkt-signer -v -v 
May 29 09:14:27 services zkt-signer: notice: "vm.freshdot.net.": re-signing triggered: Modified keys
May 29 09:14:27 services zkt-signer: notice: "freshdot.net.": re-signing triggered: Modified KSK in delegated domain
May 29 09:14:27 services zkt-signer: notice: "thesmallprint.nl.": re-signing triggered: Modified keys
May 29 09:14:27 services zkt-signer: error: zone "thesmallprint.nl.": couldn't increment serialno in file /etc/bind/master/nl/thesmallprint.nl/zone.db: no serial number found in zone file
May 29 09:14:27 services zkt-signer: notice: "freshdot.org.": re-signing triggered: Modified keys
May 29 09:14:27 services zkt-signer: error: zone "freshdot.org.": couldn't increment serialno in file /etc/bind/master/org/freshdot.org/zone.db: no serial number found in zone file
May 29 09:14:27 services zkt-signer: notice: end of run: 2 errors occured
May 29 09:15:28 services zkt-signer: notice: ------------------------------------------------------------
May 29 09:15:28 services zkt-signer: notice: running /usr/bin/zkt-signer -v -v 
May 29 09:15:28 services zkt-signer: notice: "thesmallprint.nl.": re-signing triggered: Modified keys
May 29 09:15:28 services zkt-signer: notice: "freshdot.org.": re-signing triggered: Modified keys
May 29 09:15:28 services zkt-signer: notice: end of run: 0 errors occured
May 29 09:16:05 services zkt-signer: notice: ------------------------------------------------------------
May 29 09:16:05 services zkt-signer: notice: running /usr/bin/zkt-signer -v -v 
May 29 09:16:05 services zkt-signer: notice: end of run: 0 errors occured