Slow SSH and maybe DNS issue + Startup Guide

Virtualmin
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It wasn’t clear to me the correct way to setup a virtual IP through Virtualmin that could be utilized for my second name server (yes I realize it should be a different server, but this is my test box anyhow…)

I accidentally hit change IP for all of my domains to the new one. From there, things just didn’t seem to be working right, even after I corrected them back to the old IP.

I’m having a problem right now with SSH being very slow. My root account gets right in, but any other account is several seconds to an annoying longer extra seconds.

I’m suspecting DNS, but I’m wondering if anyone has ran across this issue.

Also, did I overlook a startup or best practices guide to setting up Virtualmin Pro? Anybody working on something like this?

Ron

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Hey Ron,

I’m having a problem right now with SSH being very slow. My root account gets right in, but any other account is several seconds to an annoying longer extra seconds.

I’m suspecting DNS, but I’m wondering if anyone has ran across this issue.

I believe your suspicions are almost certainly spot on. In almost every case of “my server is slow” I’ve ever seen, the problem is DNS. The issue is probably that DNS resolution isn’t happening correctly.

Check to be sure both forward and reverse lookups work from the server:

host yahoo.com

And:

host 66.94.234.13

Both should return quickly. If they don’t, something is wrong somewhere, and it’ll slow down many network services, most notably SSH and Webmin in some circumstances.

An even better test is to figure out what IP you’re coming in on, and see if it can resolve quickly.

Also, did I overlook a startup or best practices guide to setting up Virtualmin Pro? Anybody working on something like this?

All that exists is what’s in the Administrator’s Guide here:

http://www.virtualmin.com/support/documentation/virtualmin-admin-guide/

The FAQ also has lots of specific problem+resolution docs.

There’s not really a lot to think about these days with modern Linux distributions, plus the work that the installer does automatically for you. The defaults are generally pretty sane for the vast majority of users. Though learning about the Server Templates is probably the quickest way to virtual hosting nirvana, and it seems to be the most intimidating part of Virtualmin, though I’m not really sure why (the templates configuration options are identical to those found elsewhere in Virtualmin…but something about the way we’re presenting them is scary, so nobody is creating new templates!). We’re working on understanding that problem and figuring out ways to make templates less scary. :wink:

As always if you run into any specific problems, bring them up here in the forums. We’re still learning what folks find difficult, confusing, easy to break, etc. And the documentation gets tweaked based on what we find out from people here, in the bug tracker, and in the customer issues tracker.

Even better is when we can figure out a way to make the problem disappear entirely or make the solution to a problem so obvious that documentation is unnecessary. We try that first, and documentation as a last resort…nobody reads the docs anyway (and I don’t blame them…I hate reading docs as much as anybody).

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Thanks Joe,

Excellent answer. I have actually started tweaking my templates, seems easy enough. I had already been through the admin guide - just need something more along the line of next steps.

Like setting up a Firewall, foolproof nameservers and DNS, managing resellers, what are the priorities to lock down security and get right down to business.

You really don’t get this with too many of the other control panels (besides forum posts). The biggest issue I see with Virtualmin is info overload - which is not a bad thing. But if there was a little more documentation and maybe a little better streamlining of the important stuff - I do believe you would be just about the only show in town. Especially when Ubuntu is added to the OS list.

So far everything has been excellent. --By the way - I’m not related to Joe :), that I know of at least…

One more quick question, a little off topic. Is our license tied to an IP or server specific info? I am currently running a diff control panel and the plan was to migrate the users from it to my Virtualmin server. However, when I’m done, I wanted to rebuild my hardware and load up Virtualmin and move the users from the “dev” server. I might just purchase another license, to help support a product I like - but was wondering if I could perform this action as stated without running into problems (temporarily having both servers in operation).

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Like setting up a Firewall, foolproof nameservers and DNS, managing resellers, what are the priorities to lock down security and get right down to business.

Some of these are covered by the Webmin books (Jamie’s covers more topics and is much closer to comprehensive, mine is generally considered more beginner friendly but isn’t as deep or wide). Unfortunately, both books pre-date the existence Virtualmin by a couple of months, so they only cover the Webmin and Usermin aspects of the system.

A nice thing about using Virtualmin and Webmin is that a lot of these things are not specific to our way of doing things. So, if firewalls are of interest, the iptables HOWTO is an excellent resource that will map directly to your use of Webmin’s firewall module (which is completely compatible with doing everything from the command line as well). Our install.sh will be opening the ports generally needed for hosting in a not distant release, but it’ll never be able to guess what kinds of rules your system ought to have beyond that (and be very wary of any “this firewall script is all you’ll ever need” kind of things…they’re always way more complex than they need to be, since iptables is stateful, and they address a bunch of “problems” that haven’t been exploitable in the Linux kernel since the dawn of man…so they’ll distract you from the useful rules with a bunch of stupid and pointless rules).

I’m still beating my head against the wall that is OpenACS attempting to get to the point where I can safely upgrade Virtualmin.com to the latest version. The new version will give us access to a nice WYSIWYG wiki-like document editor, so we can begin to get our users involved in the process of documentation. Not necessarily writing it, though that would be awesome too, but just giving them the ability to comment directly on the contents of the documentation so we know where we’re being opaque, confusing, or covering the wrong things.

So far everything has been excellent.

That’s wonderful to hear. We’re trying very hard to make it the best thing going.

By the way - I’m not related to Joe :), that I know of at least…

Hehehe…My full name is Ronald Joseph Cooper. If my dad weren’t already a Ron Cooper, that would be the name I answered to. According to a PBS lookup from census data, Cooper is the 58th most common surname in the US, so we’re not exactly rare. :wink:

But I also don’t have any reason to believe we’re related, but I can’t rule it out. (I’m from upstate South Carolina stock, though I don’t know much of my family on the Cooper side.)

Is our license tied to an IP or server specific info?

No. It was made clear to us early on that customers didn’t like the way other virtual host administration tools were licensing crazy. You have to get permission to sneeze with those guys, and we didn’t want folks to feel like they have to get permission for everything they do. Our licensing is very unobtrusive. You get 30 days grace, where you can run your dev server and your production server on the same license and it won’t be flagged. Even after that, there are several circumstances where it won’t be flagged.

In short, as long as you’re trying to use it honestly, you should never be aware of the license management at all. If you ever do run into it, it’s probably a bug and we apologize in advance. :wink: