For various reasons, I sometimes need to migrate accounts from one server to another server. For example, one server might be going out of service, so all accounts on it must be migrated.
I deploy servers in pairs with all content being redundantly stored via rsync from one server to the other. I also use MySQL replication to keep database data redundant. This full redundancy is required.
I'm wondering if Virtualmin/Webmin can help the process of migrating from one server to another quickly. This would also be useful in cases where one server unexpectedly goes down.
It's not clustering that I'm after... just the ability to quickly migrate accounts from one server to another. I've been doing all of this manually so far. But, maybe Virtualmin/Webmin (V/W) can do some or all of this and give me even more account safety.
Can V/W manage the work of rsync'ing and replication that I'm now doing manually?
Can V/W synchronize the UIDs/GIDs on multiple servers? And, any other data that needs to be synchronized. It can already do DNS, I see (I haven't tried it... is there a "How To" on this?)
Is there any "How To" document that helps me to take advantage of V/W in helping to migrate accounts between servers?
Is there any "How To" on IP takeover that you'd recommend using with V/W?
there is a third party module for rsync that may help.
You can install it through webmin configuration.
rsyncmin 1.146-54 Rsyncmin - Configuration of the local rsyncd.conf Stop/Start the rsync daemon on a local host. Changing its globals and the module options.
there is also Syncmin
Syncmin 1.0 This Webmin module synchronizes files between two systems, or files on the same server in a different location. To optimize the speed of the process, rsync synchronization technology is used, which only copies file differences.
Thanks for the info, Ronald.
The more I think about it, the more I realize that in bringing up a second server to work with Virtualmin, I really need a solution whereby customers can visit the control panel:
https://manage.mydomain.com
which through the reverse proxy Pound resolves to (the backend):
http://www.mydomain.com:10000
and then manage their accounts no matter which server their account is actually on. For example, if the physical servers are:
host01.mydomain.com
host02.mydomain.com
host03.mydomain.com
and if www.mydomain.com happens to be on host02.mydomain.com, then the control panel on that server would be accessed. And, if the customer's account has a domain theirdomain.com that is on host03, then when they want to make changes, add new domains, etc., the actions would need to be conveyed from host02 to host03 via Virtualmin.
Is this something that is available now? If so, how is it set up?
Would LDAP be useful in this area? There are modules in webmin for this,
I haven't tried setting that up my self and don't know too much about it, but I think you may want to look into this.
Maybe. I do see Webmin > Cluster > Cluster Users and Groups, so this makes me think that if I use Webmin's clustering, I could get much of what I need.
While I'm not looking to cluster individual accounts, if I can use Webmin/Virtualmin's capabilities for clustering users, groups, dns, etc., then maybe there's at least a solution for failover. I think that's now a good summary of what I'm after
Can Virtualmin manage failover? Or, is there any combination of things that get us there?
I don't know of a built-in way of handling this today. The VM2 product, which is nearing an official release, will assist in managing some of this.
Parts of this idea are on a bit of a long-term todo list, but in general it's a difficult problem to solve.
There's various implementations of how folks handled this sort of thing mentioned here and there in the forums -- this thread is an example that has some good info in it:
http://www.virtualmin.com/forums/general-discussion/re:rendundancy-clust...