We have a small server farm (11 now, may add more in the future) of HP Proliant DL160 G6s. They all run either Linux (server only, no X11) or VMware ESX. We had intended to get models with iLO, in case BIOS-level remote admin became an issue, but that didn't happen.

I had an IP KVM switch recommended to me (along with some sort of Remote Reboot hardware.) I've since realized that none of our machines need GUI administration, so perhaps a serial console switch would be a cheaper and more appropriate option. Something like this: http://www.kvm-switches-online.com/serimux-cs-32.html

Do you folks have an opinion on which way is a better choice? Should we go for the ease of setup (plug and go, instead of turning on the feature in the BIOS and making sure the serial settings are correct) and the flexibility of an IP KVM switch even with the extra cost? Or is a serial console switch just fine?

  • Any particular reason why you need an out-of-band solution? – Ignacio Vazquez-Abrams Apr 15 '10 at 20:35
  • The servers need to be up 24/7, and our team is spread between a few different cities and continents and time zones. My boss would like to have a failsafe that any of us can use rather than having to have someone go into the server room (especially if it's 3AM Pacific time, and I'm on vacation). I think it's a bit of overkill, but I can see why he'd like to keep his options open. – Allan Anderson Apr 15 '10 at 20:53

If an IP-KVM solution is in your budget, I'd go for that, particularly if you have the ability to remotely trigger power cycles and the like.

Can I recommend getting the type that doesn't use thick KVM cables, but instead uses CAT-5 or the like? The big cables are a PITA to run and deal with, where as we're all pretty much used to CAT-5 by now.

If you go that route, keep yourself sane by color-coding the cables so that your KVM lines don't resemble your network connections.

Serial cables do work, but the ones I've used are susceptible to interference, plus the BIOS has to support redirect-to-serial (many do now, but there's always an outlier).

  • They're all Linux, which means just spawning an instance of mingetty on ttyS0. – Ignacio Vazquez-Abrams Apr 15 '10 at 20:41
  • 1
    Don't underestimate the power of remote bios administration. How else do you rebuild a RAID array remotely? – Matt Simmons Apr 15 '10 at 20:47
  • Yes, these machines are all on RAIDs. From looking at HP's docs, I believe I can set redirect to serial in these machines' BIOS. Still, if we need to rebuild the RAID array, I guess we need to get into the room anyhow to reinstall the OS or hypervisor, eh? I know that this will be rarely used, but I'd like to make it as easy as possible for everyone in my group to use. – Allan Anderson Apr 15 '10 at 20:59
  • grahzny: Yes, reinstalling an OS requires local access (except in the case of some remote access boxes), but there are lots of BIOS settings I've been grateful for being able to access without trudging into our colo – Matt Simmons Apr 15 '10 at 21:19
  • Now something like this looks fancy! ami.com/products/… – Allan Anderson Apr 15 '10 at 22:53

I would recommend IP-KVM, especially the better models with virtual media (which means you can connect a virtual CD drive which consists of an .iso file reachable over the network). If you also have remote power control, you can do absolutely everything remotely which doesn't require direct physical access to the server (replacing or adding parts), including the installation of a hypervisor.


A full cooked solution like you consider is an option. However you can roll your own using an old PC with some serial ports (much less expensive!) and free software.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.