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Basics: What H/W do I need? - Printable Version

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Basics: What H/W do I need? - RobtCody - 2012-05-22 14:24

Hi,

I'm new to this LAN boot thing. I see this running at H&R Block (HRB) tax offices (as a tax preparer). I'm wondering what hardware is needed?

What I do know is the HRB server has many WIM files stored on it. And I presume that is our workstation images that come down our 1000MB Ethernet. I don't know if iPXE is used or not.

I noticed that if the Ethernet connection is not in place, the workstation will boot off its (still existing hard drive). If the Ethernet is working, then the existing hard drive becomes the D-Drive (and of course not booted).

I find when the client is LAN booted, its virtual C-Drive is much larger than the machines RAM. Maybe 30GB or so.

I also notice that some things are saved back at the server (such as Favorites). But we are not using Windows Roaming User Profiles or Folder Redirection.

SO MY QUESTIONS ARE:
1) Where is this 30GB virtual C-Drive?

2) Does the machine have a specialized network card that has 30GB RAM on it?

3) How does the workstation know where to find its WIM file on the server? Is this location somehow stored in the ROM of the network card?

4) I suppose the WIM file registry has been tattooed to point Favorites and My Documents back to the server's hard drive. Sound reasonable or is there a more accepted way of doing this?

5) I notice Windows is always out of date. I presume that is the problem with LAN boot images in that the systems administrator would have to update the images daily/weekly in order to keep Windows patches up to date. Same goes for the AntiVirus software. I find it months behind. Is this a typical problem with using LAN boot images or is there a way to keep to save these updates back on the server and they are automatically pulled in with each reboot of the workstation?

Thanks much for anyone that can explain these basics to me.


RE: Basics: What H/W do I need? - robinsmidsrod - 2012-05-26 10:36

My guess is that the client machines are either using iSCSI to boot, and that 30GB C drive is actually directly connected to a server via the network. Read this if you want to understand more: http://en.wikipedia.org/wiki/ISCSI

A second alternative is that they are using some kind of specialized WinPE (Preboot Environment) that runs completely in memory that mounts the C drive using CIFS/SMB file sharing (or just runs in memory). That might be why you see reports of outdated software, because the image is replaced each time you boot. It might also be possible that they use some kind of system that resets the state of the C drive on each bootup to avoid tampering by users.

I'm sure other people that have more experience with Windows deployment can give you more examples of how it's done.

The correct WIM image is most likely found by mapping the MAC address of the network card to some remote storage volume.

Question 4 might use a technology called copy-on-write volume storage, but it might also be something completely different.


RE: Basics: What H/W do I need? - RobtCody - 2012-06-09 13:25

Thanks for the answers. I suspect we are using your second alternative with the WinPE boot. I'll have to pull the ethernet wire after a boot some day, and that should tell me if it is running in RAM or file sharing. Half of our machines are thin clients (no hard drives).