Зависает сервер

Всем привет. Подскажите пожалуйста в чем может быть причина зависания сервера

Операционная система: CentOS 6 Ispmanager Lite

вот лог сервера:

Jul 15 01:36:52 vps-5682 named[996]: error (network unreachable) resolving 'pdns4.ultradns.org/AAAA/IN': 2001:502:4612::1#53

Jul 15 01:36:52 vps-5682 named[996]: validating @0xb420b4c0: . NS: verify failed due to bad signature (keyid=49656): RRSIG validity period has not begun

Jul 15 01:36:52 vps-5682 named[996]: validating @0xb420b4c0: . NS: no valid signature found

Jul 15 01:36:52 vps-5682 named[996]: error (no valid RRSIG) resolving './NS/IN': 192.58.128.30#53

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: verify failed due to bad signature (keyid=49656): RRSIG validity period has not begun

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: no valid signature found

Jul 15 01:36:53 vps-5682 named[996]: error (no valid RRSIG) resolving './NS/IN': 192.228.79.201#53

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: verify failed due to bad signature (keyid=49656): RRSIG validity period has not begun

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: no valid signature found

Jul 15 01:36:53 vps-5682 named[996]: error (no valid RRSIG) resolving './NS/IN': 192.36.148.17#53

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb421c548: . NS: verify failed due to bad signature (keyid=49656): RRSIG validity period has not begun

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb421c548: . NS: no valid signature found

Jul 15 01:36:53 vps-5682 named[996]: error (no valid RRSIG) resolving './NS/IN': 199.7.83.42#53

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: verify failed due to bad signature (keyid=49656): RRSIG validity period has not begun

Jul 15 01:36:53 vps-5682 named[996]: validating @0xb4948e88: . NS: no valid signature found

Jul 15 01:36:53 vps-5682 named[996]: error (no valid RRSIG) resolving './NS/IN': 128.8.10.90#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:500:2f::f#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:7fd::1#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:503:ba3e::2:30#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:dc3::35#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:500:1::803f:235#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:503:c27::2:30#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving 'pdns5.ultradns.info/A/IN': 2610:a1:1016::1#53

Jul 15 01:36:53 vps-5682 named[996]: error (network unreachable) resolving 'pdns5.ultradns.info/AAAA/IN': 2610:a1:1016::1#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving './DNSKEY/IN': 2001:503:c27::2:30#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:503:c27::2:30#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving './DNSKEY/IN': 2001:500:2f::f#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:500:2f::f#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:500:2c::254#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:500:60::29#53

Jul 15 02:36:52 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:4f8:0:2::20#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving './DNSKEY/IN': 2001:500:2f::f#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:500:2f::f#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving './DNSKEY/IN': 2001:500:1::803f:235#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving './NS/IN': 2001:500:1::803f:235#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:500:71::29#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:500:60::29#53

Jul 15 03:36:53 vps-5682 named[996]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:4f8:0:2::20#53

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty1) main process (1447) killed by TERM signal

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty2) main process (1449) killed by TERM signal

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty3) main process (1451) killed by TERM signal

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty4) main process (1453) killed by TERM signal

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty5) main process (1455) killed by TERM signal

Jul 15 04:18:56 vps-5682 init: tty (/dev/tty6) main process (1457) killed by TERM signal

Jul 15 04:19:09 vps-5682 abrtd: Got signal 15, exiting

Jul 15 04:19:13 vps-5682 proftpd[1373]: 127.0.0.1 - ProFTPD killed (signal 15)

Jul 15 04:19:13 vps-5682 proftpd[1373]: 127.0.0.1 - ProFTPD 1.3.4a standalone mode SHUTDOWN

Jul 15 04:19:18 vps-5682 xinetd[1123]: Exiting...

Jul 15 04:19:18 vps-5682 acpid: exiting

Jul 15 04:19:18 vps-5682 init: Disconnected from system bus

Jul 15 04:19:19 vps-5682 named[996]: received control channel command 'stop'

Jul 15 04:19:19 vps-5682 named[996]: shutting down: flushing changes

Jul 15 04:19:19 vps-5682 named[996]: stopping command channel on 127.0.0.1#953

Jul 15 04:19:19 vps-5682 named[996]: stopping command channel on ::1#953

Jul 15 04:19:19 vps-5682 named[996]: no longer listening on 127.0.0.1#53

Jul 15 04:19:19 vps-5682 named[996]: no longer listening on 91.222.139.8#53

Jul 15 04:19:19 vps-5682 named[996]: exiting

Jul 15 04:19:21 vps-5682 auditd[943]: The audit daemon is exiting.

Jul 15 04:19:21 vps-5682 kernel: type=1305 audit(1373851161.224:350): audit_pid=0 old=943 auid=4294967295 ses=4294967295 res=1

Jul 15 04:19:21 vps-5682 kernel: type=1305 audit(1373851161.332:351): audit_enabled=0 old=1 auid=4294967295 ses=4294967295 res=1

Jul 15 04:19:21 vps-5682 kernel: Kernel logging (proc) stopped.

Jul 15 04:19:21 vps-5682 rsyslogd: [origin software="rsyslogd" swVersion="5.8.10" x-pid="968" x-info="http://www.rsyslog.com"] exiting on signal 15.

Jul 15 12:19:59 vps-5682 xinetd[1138]: Started working: 0 available services

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving './DNSKEY/IN': 2001:503:c27::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving './NS/IN': 2001:503:c27::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:503:c27::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns1.ukraine.com.ua/A/IN': 2001:503:c27::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:4f8:0:2::19#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'dlv.isc.org/DNSKEY/IN': 2001:500:60::30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/A/IN': 2001:503:ba3e::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/AAAA/IN': 2001:503:ba3e::2:30#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/A/IN': 2001:500:1b::1#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/A/IN': 2001:500:19::1#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/A/IN': 2001:500:1a::1#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/A/IN': 2001:500:1c::1#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/AAAA/IN': 2001:500:1c::1#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/AAAA/IN': 2001:500:6::79#53

Jul 15 12:20:00 vps-5682 named[1011]: error (network unreachable) resolving 'ns.isc.afilias-nst.info/AAAA/IN': 2a01:8840:9::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'ns1.isc.ultradns.net/A/IN': 2001:500:1::803f:235#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'ns1.isc.ultradns.net/AAAA/IN': 2001:500:1::803f:235#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'ns1.isc.ultradns.net/AAAA/IN': 2610:a1:1014::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'ns1.isc.ultradns.net/AAAA/IN': 2001:502:f3ff::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns3.ultradns.org/A/IN': 2001:500:f::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns3.ultradns.org/AAAA/IN': 2001:500:f::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns4.ultradns.org/A/IN': 2001:500:c::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns4.ultradns.org/AAAA/IN': 2001:500:c::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns3.ultradns.org/A/IN': 2001:500:c::1#53

Jul 15 12:20:01 vps-5682 named[1011]: error (network unreachable) resolving 'pdns3.ultradns.org/AAAA/IN': 2001:500:c::1#53