hi techie,
Thanks for your interest on xCAT.
"don't want Xcat to flag the current running systems to provision.", so what features of xCAT you plan to leverage in your cluster management? is there an existing cluster management tool in your cluster?
This is an interesting question for us, since most chapters in xCAT doc focus on how to setting up a new cluster, seems we did not provide an explicit guideline on how to switching a running cluster management from other tools to xCAT.
some points I can see:
1.pick up a new virtual or physical server as xCAT management node, since xCAT installation will modify the configuration and switch the status of some system services such as dhcp/dns/httpd, reusing the management server or other servers functioning in your cluster might affect your current cluster
2. a new management subnet for xCAT you mentioned is a good start. I suggest you add the compute nodes to this subnet as well as xCAT DB gradually, do not add too many compute nodes into this subnet at your first step, especially the nodes with applications running on. For the nodes you add to xCAT, suggest to remove their configurations as well as definitions from your current cluster management tool. Then you can consider move a batch of nodes to xCAT once you are sure the whole switching process is ok
3. migration of node definitions might cost a lot of effort, xCAT provides some node discovery method(http://xcat-docs.readthedocs.io/en/stable/guides/admin-guides/manage_clusters/ppc64le/discovery/index.html), but you'e better avoid using the discovery process which requires node reboot if you do not want to affect the current cluster status. You might need to generate the node definitions in xCAT by yourself, the bmcdiscover and switchdiscover might help
4. `nodeset <node> boot` will avoid node provision on node reboot. But in some cases, the dhcp response from xcat management node might affect your current cluster management. suggest either manage the node exclusively by xCAT or stop the dhcp service on xCAT management node if you do not rely on it.
thanks
--------------------
From: techie...@gmail.com
To: xcat-user@lists.sourceforge.net
Cc:
Date: 2017年11月4日 上午12:53:39
Subject: [xcat-user] xcat integration to an existing cluster
Hi,
I am highly considering using Xcat in our current cluster, it seems to be better adaptable than other provisioning systems I have recently tried.
Having said that, if I did that, what do you recommend for integrating Xcat into a running cluster? We have over 300 nodes in the cluster, and I don't want Xcat to flag the current running systems to provision. I was thinking about starting Xcat with a new subnet, but I am not sure if that will be enough. Perhaps there is a way to just add the existing machine names, IP #'s, MAC addresses, BMC address/credentials in Xcat and set the state to 'boot' (for chain) and hopefully, Xcat will not flag them to 'image' during their next reboot or startup.
Looking for suggestions here, Thanks again for the help!
------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________ xCAT-user mailing list xCAT-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xcat-user
