nvazquez commented on code in PR #267: URL: https://github.com/apache/cloudstack-documentation/pull/267#discussion_r856344655
########## source/upgrading/upgrade/_sysvm_restart.rst: ########## @@ -15,9 +15,46 @@ .. sub-section included in upgrade notes. -Once you've upgraded the packages on your management servers, you'll +.. note:: Review Comment: This is now very long for a note :) ########## source/upgrading/upgrade/_sysvm_restart.rst: ########## @@ -15,9 +15,46 @@ .. sub-section included in upgrade notes. -Once you've upgraded the packages on your management servers, you'll +.. note:: + + From Apache CloudStack version 4.17.0 onward, there is support to live patch + system VMs, namely, SSVM, CPVM, Routers. Live patching provides support + for zero-downtime upgrades, wherein, the System VM software is updated to the + latest code version without having to destroy and recreate them / restart them. + + With this feature, users will have a choice wherein they can use the existing system VM template with the latest + software by using the live patch feature, or can follow the usual workflow of restarting the + system VM to use the latest system VM template. Live Patching system VMs serves to be especially + useful in cases when the code version has upgraded but the template hasn't. In such a scenario users + will no longer need to restart the system VMs to use the latest code. + + When one attempts to live-patch the system VMs, it pretty much mimics the patching process + that happens when booting up the System VMs but with having to shut down the system VMs. + This will update the software packages, which were previously bundled in the systemvm.iso i.e., + agent.zip and cloud-scripts.tgz and restart the services that are present in the /var/cache/cloud/enabled_svcs file + in the system VMs. This would mean the following services would be restarted: + + +-----------------+---------------------------+ + | System VM | Services | + +-----------------+---------------------------+ + | SSVM | cloud, apache2, portmap | + +-----------------+---------------------------+ + | CPVM | cloud | + +-----------------+---------------------------+ + | VRs | haproxy, apache2, dnsmasq | + +-----------------+---------------------------+ + + Also, with respect to VRs, a network restart without cleanup is initiated to ensure all rules + are re-applied. + + **NOTE:** In case there is an absolute need to upgrade the system VM template due to availability of Review Comment: Could apply ..note in this case -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: dev-unsubscr...@cloudstack.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
