dhcpd restart takes almost 7 minutes in CentOS7

Andrew Bell andrew at poscomp.ca
Sun Nov 10 14:38:48 UTC 2019


No, that's not even close to normal.  I have about 20000 leases in 70 VLANs
and my restart is less than 15 seconds.

Looking at the startup log, it seems that you have two instances running
and being restarted at the same time.  That's what you need to look at
first, I think.

On Sun, Nov 10, 2019 at 8:44 AM Cayab, Jefrey E. <jcayab at gmail.com> wrote:

> Dear dhcp-users,
>
> I have 110 dhcp scopes in my configuration file and everytime i restart
> dhcpd service, it will take 7 minutes to complete - is this normal? Is
> there a way to make it restart faster? Appreciate your help. Thank you
>
> [root at dhcp ~]#
> [root at dhcp ~]# grep VLAN /etc/dhcp/dhcpd.conf | wc -l
> 110
> [root at dhcp ~]#
> [root at dhcp ~]#
> [root at dhcp ~]# cat /etc/*release
> CentOS Linux release 7.6.1810 (Core)
> NAME="CentOS Linux"
> VERSION="7 (Core)"
> ID="centos"
> ID_LIKE="rhel fedora"
> VERSION_ID="7"
> PRETTY_NAME="CentOS Linux 7 (Core)"
> ANSI_COLOR="0;31"
> CPE_NAME="cpe:/o:centos:centos:7"
> HOME_URL="https://www.centos.org/"
> BUG_REPORT_URL="https://bugs.centos.org/"
>
> CENTOS_MANTISBT_PROJECT="CentOS-7"
> CENTOS_MANTISBT_PROJECT_VERSION="7"
> REDHAT_SUPPORT_PRODUCT="centos"
> REDHAT_SUPPORT_PRODUCT_VERSION="7"
>
> CentOS Linux release 7.6.1810 (Core)
> CentOS Linux release 7.6.1810 (Core)
> [root at dhcp ~]#
> [root at dhcp ~]#
> [root at dhcp ~]# rpm -qi dhcp
> Name        : dhcp
> Epoch       : 12
> Version     : 4.2.5
> Release     : 77.el7.centos
> Architecture: x86_64
> Install Date: Tue 01 Oct 2019 04:14:37 AM +08
> Group       : System Environment/Daemons
> Size        : 1449595
> License     : ISC
> Signature   : RSA/SHA256, Fri 23 Aug 2019 05:22:17 AM +08, Key ID
> 24c6a8a7f4a80eb5
> Source RPM  : dhcp-4.2.5-77.el7.centos.src.rpm
> Build Date  : Fri 09 Aug 2019 07:10:22 AM +08
> Build Host  : x86-01.bsys.centos.org
> Relocations : (not relocatable)
> Packager    : CentOS BuildSystem <http://bugs.centos.org>
> Vendor      : CentOS
> URL         : http://isc.org/products/DHCP/
> Summary     : Dynamic host configuration protocol software
> Description :
> DHCP (Dynamic Host Configuration Protocol) is a protocol which allows
> individual devices on an IP network to get their own network
> configuration information (IP address, subnetmask, broadcast address,
> etc.) from a DHCP server. The overall purpose of DHCP is to make it
> easier to administer a large network.
>
> To use DHCP on your network, install a DHCP service (or relay agent),
> and on clients run a DHCP client daemon.  The dhcp package provides
> the ISC DHCP service and relay agent.
> [root at dhcp ~]#
> [root at dhcp ~]#
> [root at dhcp ~]# sestatus
> SELinux status:                 enabled
> SELinuxfs mount:                /sys/fs/selinux
> SELinux root directory:         /etc/selinux
> Loaded policy name:             targeted
> Current mode:                   enforcing
> Mode from config file:          enforcing
> Policy MLS status:              enabled
> Policy deny_unknown status:     allowed
> Max kernel policy version:      31
> [root at dhcp ~]#
> [root at dhcp ~]# mount
> sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime,seclabel)
> proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
> devtmpfs on /dev type devtmpfs
> (rw,nosuid,seclabel,size=3974540k,nr_inodes=993635,mode=755)
> securityfs on /sys/kernel/security type securityfs
> (rw,nosuid,nodev,noexec,relatime)
> tmpfs on /dev/shm type tmpfs
> (rw,nosuid,nodev,noexec,seclabel,size=5242880k)
> devpts on /dev/pts type devpts
> (rw,nosuid,noexec,relatime,seclabel,gid=5,mode=620,ptmxmode=000)
> tmpfs on /run type tmpfs (rw,nosuid,nodev,seclabel,mode=755)
> tmpfs on /sys/fs/cgroup type tmpfs
> (ro,nosuid,nodev,noexec,seclabel,mode=755)
> cgroup on /sys/fs/cgroup/systemd type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd)
> pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
> cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,cpuacct,cpu)
> cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,net_prio,net_cls)
> cgroup on /sys/fs/cgroup/cpuset type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,cpuset)
> cgroup on /sys/fs/cgroup/freezer type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,freezer)
> cgroup on /sys/fs/cgroup/perf_event type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,perf_event)
> cgroup on /sys/fs/cgroup/hugetlb type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,hugetlb)
> cgroup on /sys/fs/cgroup/memory type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,memory)
> cgroup on /sys/fs/cgroup/pids type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,pids)
> cgroup on /sys/fs/cgroup/devices type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,devices)
> cgroup on /sys/fs/cgroup/blkio type cgroup
> (rw,nosuid,nodev,noexec,relatime,seclabel,blkio)
> configfs on /sys/kernel/config type configfs (rw,relatime)
> /dev/mapper/vg00-lvroot on / type xfs
> (rw,noatime,nodiratime,seclabel,attr2,inode64,noquota)
> selinuxfs on /sys/fs/selinux type selinuxfs (rw,relatime)
> systemd-1 on /proc/sys/fs/binfmt_misc type autofs
> (rw,relatime,fd=35,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=20052)
> debugfs on /sys/kernel/debug type debugfs (rw,relatime)
> hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,seclabel)
> mqueue on /dev/mqueue type mqueue (rw,relatime,seclabel)
> /dev/sda2 on /boot type xfs
> (rw,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvhome on /home type xfs
> (rw,nodev,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvtmp on /tmp type xfs
> (rw,nosuid,nodev,noexec,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvvar on /var type xfs
> (rw,nosuid,nodev,noexec,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvvartmp on /var/tmp type xfs
> (rw,nosuid,nodev,noexec,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvvarlog on /var/log type xfs
> (rw,nosuid,nodev,noexec,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> /dev/mapper/vg00-lvaudit on /var/log/audit type xfs
> (rw,nosuid,nodev,noexec,noatime,nodiratime,seclabel,attr2,discard,nobarrier,inode64,logbufs=8,noquota)
> tmpfs on /run/user/1000 type tmpfs
> (rw,nosuid,nodev,relatime,seclabel,size=797300k,mode=700,uid=1000,gid=1000)
> [root at dhcp ~]#
> [root at dhcp ~]#
>
>
> logs when "systemctl restart dhcpd" is executed:
> [root at dhcp ~]#
> [root at dhcp ~]# tail -f /var/log/messages
> Nov 10 21:16:56 dhcp polkitd[5349]: Registered Authentication Agent for
> unix-process:5937:354512872 (system bus name :1.30076 [/usr/bin/pkttyagent
> --notify-fd 5 --fallback], object path
> /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
> Nov 10 21:16:56 dhcp systemd: Stopping DHCPv4 Server Daemon...
> Nov 10 21:16:56 dhcp systemd: Stopping DHCPv4 Server Daemon...
> Nov 10 21:16:56 dhcp named[243904]: resolver priming query complete
> Nov 10 21:16:56 dhcp named[243904]: resolver priming query complete
> Nov 10 21:16:56 dhcp systemd: Stopped DHCPv4 Server Daemon.
> Nov 10 21:16:56 dhcp systemd: Stopped DHCPv4 Server Daemon.
> Nov 10 21:16:56 dhcp systemd: Starting DHCPv4 Server Daemon...
> Nov 10 21:16:56 dhcp systemd: Starting DHCPv4 Server Daemon...
> Nov 10 21:16:56 dhcp dhcpd: Internet Systems Consortium DHCP Server 4.2.5
> Nov 10 21:16:56 dhcp dhcpd: Internet Systems Consortium DHCP Server 4.2.5
> Nov 10 21:16:56 dhcp dhcpd: Copyright 2004-2013 Internet Systems
> Consortium.
> Nov 10 21:16:56 dhcp dhcpd: Copyright 2004-2013 Internet Systems
> Consortium.
> Nov 10 21:16:56 dhcp dhcpd: All rights reserved.
> Nov 10 21:16:56 dhcp dhcpd: All rights reserved.
> Nov 10 21:16:56 dhcp dhcpd: For info, please visit
> https://www.isc.org/software/dhcp/
> Nov 10 21:16:56 dhcp dhcpd: For info, please visit
> https://www.isc.org/software/dhcp/
> Nov 10 21:16:56 dhcp dhcpd: Warning: subnet 192.168.88.0/24 overlaps
> subnet 0.0.0.0/-26
> Nov 10 21:16:56 dhcp dhcpd: Warning: subnet 192.168.88.0/24 overlaps
> subnet 0.0.0.0/-26
> Nov 10 21:17:12 dhcp dhcpd: WARNING: Host declarations are global.  They
> are not limited to the scope you declared them in.
> Nov 10 21:17:12 dhcp dhcpd: WARNING: Host declarations are global.  They
> are not limited to the scope you declared them in.
> Nov 10 21:17:12 dhcp dhcpd: Not searching LDAP since ldap-server,
> ldap-port and ldap-base-dn were not specified in the config file
> Nov 10 21:17:12 dhcp dhcpd: Not searching LDAP since ldap-server,
> ldap-port and ldap-base-dn were not specified in the config file
> Nov 10 21:17:12 dhcp dhcpd: Internet Systems Consortium DHCP Server 4.2.5
> Nov 10 21:17:12 dhcp dhcpd: Internet Systems Consortium DHCP Server 4.2.5
> Nov 10 21:17:12 dhcp dhcpd: Copyright 2004-2013 Internet Systems
> Consortium.
> Nov 10 21:17:12 dhcp dhcpd: Copyright 2004-2013 Internet Systems
> Consortium.
> Nov 10 21:17:12 dhcp dhcpd: All rights reserved.
> Nov 10 21:17:12 dhcp dhcpd: All rights reserved.
> Nov 10 21:17:12 dhcp dhcpd: For info, please visit
> https://www.isc.org/software/dhcp/
> Nov 10 21:17:12 dhcp dhcpd: For info, please visit
> https://www.isc.org/software/dhcp/
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 class decls to leases file.
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 class decls to leases file.
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 deleted host decls to leases file.
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 deleted host decls to leases file.
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 new dynamic host decls to leases file.
> Nov 10 21:23:12 dhcp dhcpd: Wrote 0 new dynamic host decls to leases file.
> Nov 10 21:23:13 dhcp dhcpd: Wrote 60199 leases to leases file.
> Nov 10 21:23:13 dhcp dhcpd: Wrote 60199 leases to leases file.
> Nov 10 21:23:13 dhcp dhcpd: Listening on LPF/eth0/50:6b:8d:03:a8:b9/
> 0.0.0.0/0
> Nov 10 21:23:13 dhcp dhcpd: Sending on   LPF/eth0/50:6b:8d:03:a8:b9/
> 0.0.0.0/0
> Nov 10 21:23:13 dhcp dhcpd: Sending on   Socket/fallback/fallback-net
> Nov 10 21:23:13 dhcp systemd: Started DHCPv4 Server Daemon.
> Nov 10 21:23:13 dhcp dhcpd: Listening on LPF/eth0/50:6b:8d:03:a8:b9/
> 0.0.0.0/0
> Nov 10 21:23:13 dhcp dhcpd: Sending on   LPF/eth0/50:6b:8d:03:a8:b9/
> 0.0.0.0/0
> Nov 10 21:23:13 dhcp dhcpd: Sending on   Socket/fallback/fallback-net
> Nov 10 21:23:13 dhcp systemd: Started DHCPv4 Server Daemon.
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>
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