Given that the c5 instances are Skylake, and I read somewhere that there’s some special edge-case for Skylake and later CPUs, is this reproducible on proper hardware, or is it limited to KVM (prior to AWS’s c5s, the hypervisors were xen).
I’ve got a couple of Skylake machines available, and will install sssd and see what happens. Cheers, David > On 5 Feb 2018, at 21:59, Paul Friel <1746...@bugs.launchpad.net> wrote: > > @jsalisbury: I installed that kernel and rebooted using a c5.xl, it > froze. I booted into a c4.xl and it booted fine, disabled the apparmor > service and rebooted into a c5.xl and it booted fine. Re-enabled > apparmor and rebooted into the c5.xl again and it froze on boot. > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/1746806 > > Title: > sssd appears to crash AWS c5 and m5 instances, cause 100% CPU > > Status in cloud-images: > New > Status in linux package in Ubuntu: > Confirmed > Status in linux-aws package in Ubuntu: > Confirmed > Status in sssd package in Ubuntu: > Confirmed > > Bug description: > After upgrading to the Ubuntu EC2 AMI from 20180126 (specifically > ami-79873901 in us-west-2) we have seen sssd hard locking c5 and m5 > EC2 instances after starting the service and CPU goes to 100%. > > We do not experience this issue with t2 or c4 instance types and we do > not see this issue on any instance types using Ubuntu Cloud images > from 20180109 or before. I have verified that this is kernel related > as I booted an image that we created using the Ubuntu cloud image from > 20180109 which works fine on a c5. I then did a "apt update && apt > install --only-upgrade linux-aws && systemctl disable sssd", rebooted > the server, verified I was on the new kernel and started sssd with > "systemctl start sssd" and the EC2 instance froze and Cloudwatch CPU > usage for that instance went to 100%. > > I haven't been able to find much in the syslog, kern.log, journalctl > logs, etc. The only thing I have been able to find is that when this > happens I tend to see "^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@" in > the syslog and sssd log files. I have attached several log files and > the output of a "apport-bug /usr/sbin/sssd". Let me know if you need > anything else to help track this down. > > Thanks, > Paul > > To manage notifications about this bug go to: > https://bugs.launchpad.net/cloud-images/+bug/1746806/+subscriptions -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1746806 Title: sssd appears to crash AWS c5 and m5 instances, cause 100% CPU To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1746806/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
