Dear Maintainer,

I'm not sure this really belongs to isc-dhcp-client, and may deserve attention from other maintainers, but I couldn't find a better place for reportbug.

If a debian jessie system is rebooted with grub's default "recovery mode", and if there's no separate /var partition, the / partition cannot be remunted read-only, because there's a lease file used by dhclient inside /var.

mount -n -o remount,ro will report : mount: / is busy

Indeed /var/lib/dhcp/dhclient.eth0.leases is reported as opened in w mode by lsof.

I believed it may not be ideal to keep dhclient running when in recovery mode, although I'm not qualified enough to know whether it's systemd's duty to stop it for instance.

In any case, killall dhclient is a workaround that allows remounting / read-only.

Hope this helps.

Thanks in advance.

Best regards,

control: severity -1 wishlist
control: reassign -1 rescue-mode
control: retitle -1 rescue-mode: option to select mounting as ro or rw

As mentioned elsewhere ro can be passed as a kernel option.  Or you can do

# mount -o remount,ro /target

before entering the target.

I did some testing.  The network is brought up and configured in the
d-i environment, not the rescue mode target's environment, so for my
testing dhclient never got launched.  Can you better describe the
exact steps to recreate the problem?

I think what you're really looking for is an option in the rescue mode
dialogs to select whether mounting is attempted as ro or rw.

Best wishes,
Mike