This month’s come together will be held on 2017-11-01, 8pm at our regular pub (Trödler).
For almost two years Mike Rapoport and I have been working on lazy process migration. Lazy process migration (or post-copy migration) is a technique to decrease the process or container downtime during the live migration. I described the basic functionality in the following previous articles:
Those articles are not 100% correct anymore as we changed some of the parameters during the last two years, but the concepts stayed the same.
Mike and I started about two years ago to work on it and the latest CRIU release (3.5) includes the possibility to use lazy migration. Now that the post-copy migration feature has been merged from the criu-dev branch to the master branch it is part of the normal CRIU releases.
With CRIU’s 3.5 release lazy migration can be used on any kernel which supports userfaultfd. I already updated the CRIU packages in Fedora to 3.5 so that lazy process migration can be used just by installing the latest CRIU packages with dnf (still in the testing repository right now).
More information about container live migration in our upcoming Open Source Summit Europe talk: Container Migration Around The World.
Another interesting change about CRIU is that it started as x86_64 only and now it is also available on aarch64, ppc64le and s390x. The support to run on s390x has just been added with the previous 3.4 release and starting with Fedora 27 the necessary kernel configuration options are also active on s390x in addition to the other supported architectures.
As I’m currently switching phones I had to revisit the issue of how to get sshd running on a pristine LineageOS install. I decided to collect the steps here as the how-to formerly available on the CM wiki has vanished together with CM itself. Note that some steps are not incredibly detailed and you really should be aware of the security implications before going ahead with this.
- a device with a current LineageOS 14.1 build installed
- USB debugging enabled
- root access (preferably by installing the official SU addon)
- if you want sshd to run automatically after boot, you have to be willing to install my little RunUserInit hack and allow it to acquire root privileges
While LineageOS includes all necessary software, the configuration of sshd must be completed manually:
- Connect the device via USB
- Run adb with root privileges:
- Upload your public ssh key to the device:
adb push ~/.ssh/id_rsa.pub /data/ssh/authorized_keys
- Now, open a root shell and switch to bash to get vim to behave nicely on the device through adb:
- Use cat or vim to make the following fragment the contents of /data/ssh/sshd_config:
Subsystem sftp internal-sftp
- Place a modified version of the start script in the userinit.d directory:
sed 's#/system/etc/ssh#/data/ssh#' /system/bin/start-ssh
- Now correct the file privileges:
chmod 755 /data/local/userinit.d/99sshd
chmod 600 /data/ssh/authorized_keys
chown shell /data/ssh/authorized_keys
chmod 644 /data/ssh/sshd_config
Now you should be able to run sshd manually by executing
If so you can log on as user shell to the device using your ssh key. See my previous post to find out how you can make sure sshd is started whenever the device is booted.
Added IPv6 reverse record for 2001:7c0:700::10 – rhlx01.hs-esslingen.de
Added AAAA record for rhlx01.hs-esslingen.de – 2001:7c0:700::10
Enabled IPv6 address 2001:7c0:700::10
It is a bit late but I still wanted to share my presentations from this year’s Linux Plumbers Conference:
On my way back home I had to stay one night in Albuquerque and it looks like the hotel needs to upgrade its TV system. It is still running Fedora 10 which is EOL since 2009-12-18: