I cleared some more queries regarding leasesfile-ro option. Once can read the conversation at http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2014q2/008656.html.
TL;DR: (i) We have to change the leasehelper program to honor the event 'init' and print leases info in dnsmasq leases format (so that dnsmasq knows about previous leases if it is restarted for some reason).
Bummer. When 'init' is sent to the leases helper program, the interface name is not known :'( so the helper program doesn't know which *.status file it has to read and print to stdout. Simon came up with the following hack: "" The most obvious nasty hack to make this work would be to have a set of filesystem links to the real lease-change script, each with a different name, and configure each dnsmasq to call a unique link. The script then checks argv[0] to find the name it was called by and then transforms that into the name of the corresponding database file. So we have something like scripts/interface1 is a link to /lib/libvirt/lease-change- script scripts/interface2 is a link to /lib/libvirt/lease-change-script and start dnsmasq with dnsmasq --interface=interface1 --dhcp-script=scripts/interface1 and the script finds the basename of argv[0[: scripts/interface1 -> interface1 and prepends the directory where the lease files are interface1 ->leasefiles/interface1 That works in the absence on the DNSMASQ_INTERFACE variable. "" Is this hack acceptable? -- Nehal J Wani