PXE - Diskless Booting

It sometimes makes sense to boot without a hard drive. This can be done by PXE booting. The motherboard / NIC has to support it and it is not exactly common, but it allows you to manage desktop OS installs like VM images. Very flexible and robust. I don't use it to manage 10 boxes but managing 20+ as some people do here, I could see a need for something like that.

One of the better PXE solutions out there is a company called Ardence, which was acquired by Citrix.

Here is a great video of them showing off their software on around 250 some odd computers.

http://www.youtube.com/watch?v=moIuHqIc-PQ

Their software, as usual, is not cheap. It is designed for the enterprise IT setting. There are other methods out there - Red Hat has something like this built in to their kernal and there are several other vendors out there that will enable this.

how does a diskless system run games though. I would imagine with a stripped down OS ran 100% out of the ram, wouldnt graphical games still suffer a bit in performance without a big chunk of ram.

in order words, the amount saved in hard drives would be replaced with greater ram costs, so the savings is really only on ease of upgrade.

I wish I could play with things like that all day.

Wouldn't mind getting Gameslah's input on this, since he seems to have a good grasp of diskless wow.

I *might* delve into it.... I have a few applications in mind that could benefit greatly from it.

Not sure its worth it for 10 boxing though..... especially considering I already have the drives.

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Originally Posted by Xzin

Red Hat has something like this built in to their kernal and there are several other vendors out there that will enable this.

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I havent found any other solution than Ardence for WinXP/Vista/W2k, but for Linux and Win98 i've found even too many.

On a side note - every linux is really easy to boot off from network. Create custom pxelinux-loader, and tell from which NFS address it can find it's root disk and you are on your way. Every decent distro has tools for this (RedHat, SuSe, Ubuntu, Debian, Slackware and so on..)
You can even use GRUB or Lilo to boot off from network (do multiboot setup, 1 for XP and 1 for network boot -> choose at bootup) and so on.

Ardence's unique contribution to this issue is the disk driver for XP that it can use network drive as virtual disk. That would be all i need for diskless XP that i want to build, but no other vendors seem to offer it now.
And Ardences representative in my country is... piss poor. They wont even send the prices :(

So is this how one would set up a server and 5 stations for vboxing?

Don't have to, no. Just allows hard drive free booting.

HowtoForge has a good article on getting a PXE server up with DHCP, TFTP, and how to boot up various Linux versions with it. This is a good start for anyone that doesn't mind using Linux to get their feet wet. Samba comes on most Linux installs and it can be used to share files to the Windows clients.

BartPE is a program for creating a live boot CD/DVD for various versions of Windows. He used to have a Network boot disk version but it is no longer maintained (might still work though). I've tried creating a Windows XP image to boot through my CD with good results. It should be pretty straight forward to push it via Linux but I haven't devoted an afternoon or night to put all the pieces together.

An all windows setup is possible but I haven't found anything yet that wasn't overly expensive. I'll post my notes once I get everything working but I thought the more adventurous of you might benefit from the little bit that I've found so far.

While it would make managing the operating system slightly easier, you could accomplish mostly the same thing (with MUCH faster swapfile times) by buying some dirt cheap $5 drives off ebay to boot the OS, and then pulling your copies of Wow over the network from a central storage system.

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Originally Posted by Jon3

While it would make managing the operating system slightly easier, you could accomplish mostly the same thing (with MUCH faster swapfile times) by buying some dirt cheap $5 drives off eBay to boot the OS, and then pulling your copies of Wow over the network from a central storage system.

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You're right a hard drive solution would be quicker. I'd personally rather not have a disk in the machines to cut down on heat and noise (updates too). For most people I would agree that a disk based setup is the optimal way to go or even booting with a BartPE CD / DVD is reasonable way to go.

I can run swapless on 2G of RAM (with no noticeable performance problems and plenty of free RAM on a non-PXE boot) so I was planning on using 3G to 4G of ram on my PXE clients to help give them more breathing room.

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Originally Posted by esoterik

how does a diskless system run games though. I would imagine with a stripped down OS ran 100% out of the ram, wouldnt graphical games still suffer a bit in performance without a big chunk of ram. in order words, the amount saved in hard drives would be replaced with greater ram costs, so the savings is really only on ease of upgrade.

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Your replacing the bootdrive with an image of a disk that is over the network. Think when you 'boot from floopy? boot from cd' well this is 'boot from network'

Its at this point that you desire to leverage the speed of the network over the speed of the IDE connection. You can also boot the same image on various computers at the same time. Its at this point that the network file server desires to leverage its powerful disk caching, filesystem performance optimizations and network prowess abilities and attributes.

This comes in handy when all five clients zone at the same time. The file server should have that information read super quick and be able to send it to the multiple clients blocked correctly and sustained.

While you boot remotely, that doesn't mean you cannot use non-boot disks locally. Though potentially this might be backwards linking to some people, but for things such as swap space this can make sense.

But remember that depending on your setup, there should be very little writing done by the clients and extra memory freed up with the potential absence of hardware.

Obviously your not going to want to run itunes or fraps on one of these setups. These are for lean optimized setups.

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Originally Posted by hpavc

Your replacing the bootdrive with an image of a disk that is over the network. Think when you 'boot from floopy? boot from cd' well this is 'boot from network'

Its at this point that you desire to leverage the speed of the network over the speed of the IDE connection. You can also boot the same image on various computers at the same time. Its at this point that the network file server desires to leverage its powerful disk caching, filesystem performance optimizations and network prowess abilities and attributes.

This comes in handy when all five clients zone at the same time. The file server should have that information read super quick and be able to send it to the multiple clients blocked correctly and sustained.

While you boot remotely, that doesn't mean you cannot use non-boot disks locally. Though potentially this might be backwards linking to some people, but for things such as swap space this can make sense.

But remember that depending on your setup, there should be very little writing done by the clients and extra memory freed up with the potential absence of hardware.

Obviously your not going to want to run itunes or fraps on one of these setups. These are for lean optimized setups.

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Sorry, I've been lurking on these forums for a little while, but I had to create an account to respond to this incorrect information. The speed of a diskless workstation is always, always, going to be slower than a workstation with a hard drive in it. Why? Simply because you have more bandwidth to your IDE hard drive than you do to the network. IDE hard drives operate at 133 megabytes a second (across the IDE bus). SATA drives operate at ~150 megabytes a second, or if you have the newer SATA2 drives, ~300 megabytes a second (3 gigabits).

Your ethernet network, even if it is gigabit, is a hell of a lot slower than 3 gigabits. Factor in TCP/IP overhead (you never get 100% of the gigabit speed), and the fact that the file server has to read the same information off of it's hard drives, which, unless they are SCSI or FCAL (fibre channel) disks, are going to be the same speed as the ones in the workstation would have been anyway, and it's now noticeably slower.

Oh, and having 5 workstations, all attempting to load an instance at the exact same time, crushing your poor file server with their requests, is just asking for problems. I suspect that 2 minute zoning times would not be out of the question.

The reason to go diskless is ease of managing all of those workstations, and heat and power requirements of hard drives; not performance. Unless you're willing to spend thousands of dollars on a Network Appliance http://www.netapp.com and setup iSCSI boot to all of your Windows clients (requires special network cards), you're going to be suffering on performance and reliability as well.

illumin8 what yer quoting is interface max speeds not actual drive speeds the fastest drive I can find at the moment is a Seagate Cheetah 15K.5 (300 GB Ultra320 SCSI) - 135.0 MB/Sec it also cost a small fortune.

The interfaces are designed to be able to handle more the one drive without getting bogged down.

High end sata drive average around 88 MB/Sec these are read speeds write would be slower.

When yer loading, the whole game isn't 3 gigs, at most at any one time yer loading maybe about 300-500 megs of data.

I think gigabit ethernet card would more then suffice.

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Originally Posted by wowphreak

illumin8 what yer quoting is interface max speeds not actual drive speeds the fastest drive I can find at the moment is a Seagate Cheetah 15K.5 (300 GB Ultra320 SCSI) - 135.0 MB/Sec it also cost a small fortune.

The interfaces are designed to be able to handle more the one drive without getting bogged down.

High end sata drive average around 88 MB/Sec these are read speeds write would be slower.

When yer loading, the whole game isn't 3 gigs, at most at any one time yer loading maybe about 300-500 megs of data.

I think gigabit ethernet card would more then suffice.

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Yeah, they are max interface speeds, but on a SATA drive, that's a dedicated bus to your computer. Start using diskless and now you're sharing your gigabit interface with 5 other clients. No longer dedicated. And from my tests, gigabit ethernet, unless you're using jumbo frames, doesn't usually get faster than about 500-600 megabits (60-70 megabytes a sec). Divide by 5 and you'll probably get roughly 12-15 MB a second when loading all 5 clients at once.

Not idea for performance. Nice for manageability though.