On 27/07/18 21:15, Gene Heskett wrote:
On Friday 27 July 2018 12:29:34 Mark Morgan Lloyd wrote:
I found the 8.8.8.8 in /etc/resolvconf/resolvconf.d/head and changed it to point at the router, and rebooted since a service networking restart hung and never came back from this machines login.
For a local router you're probably better using a gateway in /e/n/interfaces and then removing anything hardwired in the head or tail file.
Pulled the sd card from the pi and dd'd it to a file that was just short of 32GB, took about an hour, but its writing slower and is still blinking away at putting that file on a 64GB sd card for a backup after nearly 2 hours. With 64GB, and I don't care if it never gets resized as that 32GB is way more than enough to hold this install.
You can speed it up by using e.g. bs=128M so that dd is handling larger chunks. Keep a note with the card so that you know you that you don't have to back the whole 64Gb up.
And it sharpened a table saw blade far sharper than anything I can buy, using a dremel at about half speed, driving the cable wand bolted to the mini-mills head casting which had a 1.5" diameter diamond disk mounted.
Neat but I'm afraid very much off-topic.
What appears to be happening is that both dhcpcd and NetworkManager are being started by systemd, and while NetworkManager can be relied on to leave interfaces mentioned in /e/n/interfaces alone it appears that dhcpcd is nowhere near as well-behaved. I'm unsure about the side-effects of this, but for the sake of getting things to a testable state dhcpcd can be disabled using something like # systemctl stop dhcpcd # systemctl disable dhcpcd # systemctl mask dhcpcd That restores things to the "classic Debian" state where /e/n/interfaces is obeyed, but where NetworkManager will try to handle any interfaces that are not explicitly listed (in particular WiFi). If one doesn't want NetworkManager, then it can be disabled in a similar fashion. I'd suggest not trying to uninstall it.
I've just been looking at removing dhcpcd5 which appears to be redundant and the cause of the original gateway problem. However on the TinkerBoard doing that also removes tinker-config which would be undesirable.
It's possible to configure dhcpcd to ignore certain types of interface, but I can't see a way to tell it not to try to preempt /e/n/interfaces. However this is by no means the first time that I've found inconsistencies in this area.
Noted JP's previous comments that systemd should be allowed to handle much of this stuff, but e/n/interfaces concentrates most of the interface configuration in one place and as long as it's installed by default it's reasonable to expect it, and its extensions, to work. And before it's deprecated and removed I trust that somebody will document and test its replacement, and test that all combinations of the replacement extensions interwork correctly.
-- Mark Morgan Lloyd markMLl .AT. telemetry.co .DOT. uk [Opinions above are the author's, not those of his employers or colleagues]
