I'm experiencing this issue too with artful on c5.large. During the
installation of sssd-common 1.15.3-2ubuntu1, the last line of output is
"Warning failed to create cache: usr.sbin.sssd" before the instance
becomes unresponsive. If I use t2.medium, I don't experience this issue.
Regions tested: us-west-2 and eu-west-1
I do believe that I've experienced this issue without installing sssd,
sometimes the machine fails to boot from the initial launch of the AMI.
It freezes at "kernel: iscsi: registered transport (iser)"
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sssd appears to crash AWS c5 and m5 instances, cause 100% CPU
Status in cloud-images:
Status in linux package in Ubuntu:
Status in sssd package in Ubuntu:
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.
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