Web Hosting Talk : Web Hosting Main Forums : Colocation and Data Centers : server management via serial console

[superman_1972]

My servers have a serial console port.

How can this be used to access them remotely in case the server is offline through the normal ethernet port?

What extra hardware do I need and how do I need to configure freebsd 4.10 to do this?

Is it true that I can use this port to access my server remotly as if I was actually in the data center?

[rackguru]

You redirect your console to the serial port. Your machine probably supports BIOS redirect as well. Depending how the setup is done, you would ssh to a box on a port or via a ssl webpage, etc. If you are running a non-graphical OS such as *nix, it is the very same console that you see on the monitor, just redirected.

[superman_1972]

thanks, its an isp1100, yes it does support bios redirect.

my question is what is the hardware I have to plug into this serial port and how do I re-configure freebsd to go through it so I can ssh into my server in case its not reachable via the normal way like when its down (like right now.)

this would save me from having to go to the datacenter...

[racksense]

Ordinarily you need a serial console server, but for a single machine you may be able to find a single port ethernet<->serial device of some description.

If the BIOS redirection is intelligent enough it may work all the way through to the FreeBSD login prompt although usually you'll find it only copes with the BIOS and that's it.

On FreeBSD, simply echo '-P' > /boot.config and then change /etc/ttys so that ttyd0 is 'on' and change std.9600 to 3wire.9600, that's pretty much all you need.

[superman_1972]

so you are saying that it only gets me the bios not the actual screen after bios is up? yes/no?

what about if I use this product?

http://www.lantronix.com/data-center...00-scs400.html

Lantroix SCS100/SCS200/SCS400
Console Management Solutions

[racksense]

so you are saying that it only gets me the bios not the actual screen after bios is up? yes/no?

Using the BIOS redirection on its own.. no.
Using with the FreeBSD instructions above.. yes.

what about if I use this product?

Should do the job.

[bqinternet]

If your motherboard supports console redirection, it should give you access through the console up until the FreeBSD boot loader. At that point, your boot loader and your kernel will need to be configured to use the serial console.

If you have multiple servers, you may not need any special console server. We prefer to hook up pairs of servers (server1 COM1 to server2 COM2, server2 COM1 to server1 COM2), then SSH in and use the cu utility to access the console.

[superman_1972]

so your saying you use a second server as the console server since its not likely that both will go down at the same time?

[bqinternet]

Originally posted by superman_1972
so your saying you use a second server as the console server since its not likely that both will go down at the same time?

Yes. Assuming your servers have 2 serial ports each, it's quite economical.

[superman_1972]

can you link me to the cu utility info?

[superman_1972]

never mind I found it...

http://www.onlamp.com/pub/a/bsd/2001...cs.html?page=2

[fastdeploy]

Originally posted by superman_1972
thanks, its an isp1100, yes it does support bios redirect.

my question is what is the hardware I have to plug into this serial port and how do I re-configure freebsd to go through it so I can ssh into my server in case its not reachable via the normal way like when its down (like right now.)

this would save me from having to go to the datacenter...

I would tend to disagree with the daisy-chain approach to serial console control unless you just have a few servers and don't plan on scaling much. If you don't, ignore my advice and use the second serial port (which isn't available on a lot of server cases) or purchase a multi-serial RJ45-based card like SIIG and other vendors make and put it in a PCI slot.

If you really want serial console support get a nicer multi-port terminal server that supports higher densities and reverse telnet like a Livingston PM25 (End-of-Life but <$200 for 24 ports), Cisco 2511 ($250 for 16 ports off eBay), or if you want support a Digi or Cyclades console server. The Lantronix look a bit retarded to me.

[superman_1972]

does is PM25 support SSH? or is reverse telnet pretty secure?

can you show me some info on these like white papers, docs?

[superman_1972]

http://portmasters.com/www.livingston.com/

answeriing my own questions here

above is what I found for docs on the pm25

[apexio]

I got a sealed PM-25 off ebay for about $50. Picked up the cables from portmasters.com but I haven't gotten around to setting it up yet. It seems like it will work nicely. I plan to SSH into a local box and then telnet to the PM-25 to keep things secure.