I have multiple VMs that are hanging on boot. Sometimes they'll boot fine after 5 mins and other times it'll take over an hour. The problem seems to be related to journald but I'd like to figure out how I can get more information. The VMs are running CentOS 7.1.1503. systemd and journald are both version 208. We are reluctant to upgrade to the newest CentOS because we found that journal-gatewayd is broken on boxes that have been upgraded.

If I add the kernel parameter systemd.log_target=console then they boot up fine without hanging at all. I can't seem to get into the debug shell (Ctrl+Alt+F9) while the system is hanging after enabling debug-shell. Adding systemd.log_level=debug without systemd.log_target=console seems to make the problem worse and causes a hang of over an hour. I tried deleting /var/log/journal but that didn't help and I ran fsck on the root drive with no errors. I also tried masking systemd-udev-settle but that didn't help either.

While the system is hanging the last console output is "Welcome to CentOS Linux 7 (Core)!".

Here's the output from dmesg without "quiet" kernel parameter and without "systemd.log_level=debug": http://gobin.io/zScc

systemd-analyze blame doesn't seem to help either (top 3): 10.451s nginx.service 7.149s network.service 2.178s etcd.service

What else can I do to debug this?

Thanks!