On Mon, 06.04.15 22:16, Paul Menzel (paulepan...@users.sourceforge.net) wrote:
> Am Freitag, den 03.04.2015, 16:47 +0200 schrieb Lennart Poettering: > > On Thu, 02.04.15 13:11, Paul Menzel wrote: > > > > some network cards with certain cables and devices take up to five > > > seconds so that the link is up [1]. > > > > > > $ sudo journalctl -u systemd-networkd > > > -- Logs begin at Fr 2015-03-20 17:39:31 CET, end at So 2015-03-22 > > > 08:39:39 CET. -- > > > Mär 20 17:39:31 myhostname systemd-networkd[245]: lo > > > : gained carrier > > > Mär 20 17:39:31 myhostname systemd-networkd[245]: eth0 > > > : link configured > > > Mär 20 17:39:34 myhostname systemd-networkd[245]: eth0 > > > : gained carrier > > > > > > This is annoying if the system is up, but you cannot log into a server > > > because the NIC is so slow configuring the link. > > > > > > The Linux kernel module developers from the e1000-devel mailing list > > > suggested the following [2]: > > > > > > > Both sides either need to be forced or both sides need to be auto-neg. > > > > Otherwise the auto-negotiation process will usually detect link (the > > > > physical signal) but fail to find duplex (since one side is not > > > > talking) and default to the lowest common denominator, e.g. half > > > > duplex. So, you could try forcing speed, it may look right on your > > > > end but if you have no visibility to the other end it could be running > > > > at half duplex. > > > > > > > > You may be able to speed up the auto negotiation process by > > > > exclusively advertising 1000 Mbps Full Duplex. > > > > > > > > # ethtool -s ethX advertise 0x20 > > > > > > In the IRC channel #syst...@irc.freenode.net somebody told me to look > > > into systemd’s network link configuration (`man systemd.link`). > > > > > > Reading the manual page, it’s not clear to me, if auto-negotiation is > > > going to be disabled, if the following is set. > > > > > > BitsPerSecond=1G > > > Duplex=Full > > > > > > Is that equivalent to `ethtool -s ethX advertise 0x20`? If not, how > > > could I set that up? > > > > BitsPerSecond= and Duplex= are equivalent to "ethtool speed" and > > "ethtool duplex". > > > > We currently have no setting in .link files that was equivalent to > > "ethtool advertise". Maybe we could add that, Tom? > > > > Paul, are you sure that this will really cut 5s from the configuration > > time? Did you try this? > > I am not sure and didn’t try this, as I do not know where to integrate > that `ethtool -s eth0 advertise …` call. In udev or `systemd-networkd`? > > If somebody could help me, how I can test this, I’ll report my findings > back. Wouldn't it suffice to unplug the ethernet cable, then use ethtool to turn this on, then replug it, and measuring the time until networkd notices the link beat is back? Lennart -- Lennart Poettering, Red Hat _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
