Root Partition full due to dnsmasq.log files in vCenter Server Appliance or Platform Service Controller

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• The root partition on the vCenter Server Appliance or Platform Service Controller is full, or nearing full.
• You see that dnsmasq.log files are available on the root partition.

Environment

VMware vCenter Server Appliance 6.0.x
VMware vCenter Server Appliance 6.5.x

Cause

This issue occurs because dnsmasq.log is being directed to /var/log/ instead of /var/log/vmware/.

Resolution

This issue is resolved in:

• vCenter Server 6.0 U3g, available at VMware Patch Downloads.
• vCenter Server 6.5 U2, available at VMware Downloads.

Workaround:
To work around this issue, update the below files:

1. Open an SSH connection to the vCenter Server Appliance (VCSA) or Platform Service Controller.
2. Modify the below file with a text editor:
   
   vi /etc/logrotate.d/dnsmasq
   
   Update the file to contain these lines and save the file:
   /var/log/vmware/dnsmasq.log {
   nodateext
   daily
   missingok
   notifempty
   compress
   size 5M
   rotate 5
   sharedscripts
   postrotate
   [ ! -f /var/run/dnsmasq.pid ] || kill -USR2 `cat /var/run/dnsmasq.pid`
   endscript
   create 0640 dnsmasq dnsmasq
   }
    
3. Modify the below file with a text editor:
   
   /etc/dnsmasq.conf
   
   Update the file to contain these lines and save the file:
   
   listen-address=127.0.0.1
   bind-interfaces
   user=dnsmasq
   group=dnsmasq
   
   no-negcache
   no-hosts
   log-queries
   log-facility=/var/log/vmware/dnsmasq.log
   domain-needed
   dns-forward-max=150
   cache-size=8192
   neg-ttl=3600
4. Restart the dnsmasq service by running this command:
   service dnsmasq restart

Additional Information

What is dnsmasq?

The following Debian Wiki page describes the dnsmasq package as follows:

Disclaimer: VMware is not responsible for the reliability of any data, opinions, advice, or statements made on third-party websites. Inclusion of such links does not imply that VMware endorses, recommends, or accepts any responsibility for the content of such sites.

dnsmasq is a lightweight, easy to configure, DNS forwarder and DHCP server. It is designed to provide DNS and optionally, DHCP, to a small network. It can serve the names of local machines which are not in the global DNS. The DHCP server integrates with the DNS server and allows machines with DHCP allocated addresses to appear in the DNS with names configured either in each host or in a central configuration file. dnsmasq supports static and dynamic DHCP leases and BOOTP/TFTP for network booting of diskless machines.

The dnsmasq subsystem works as follows:

1. The dnsmasq package accepts DNS queries.
2. The dnsmasq package then either answers the DNS queries from its small, local cache or forwards them to a real, recursive, DNS server.
3. The dnsmasq package also loads the contents of /etc/hosts so that local hostnames which do not appear in the global DNS can be resolved and also answers DNS queries for DHCP configured hosts. The dnsmasq package can thus act as the authoritative DNS server for one or more domains, allowing local names to appear in the global DNS.