[INFO] PXE (Small General Overview)
Posted: 16 Jun 2011, 05:19
PXE is short for Preboot Execution Envionment.
Short and simple definition this PXE allows us to boot the computer over the network not requiring
harddrive nor cdrom. You can do this with as few as 2 computers (1 server, 1 client), or as many as
can get your hands on.
Reasons for PXE booting:
$43.99 8 gb ssd
$14.99 40 gb ultra ata
$17.94 39 gb sata
$4 to $20 cdrom device
These prices are from pricewatch night of June 11, 2011.
So if we are setting up a network with 101 computers(1 server, 100 clients) we could potentially save
(100 X (cost of harddrive)) + (100 X (cost of cdrom)). And those were the cheapest data storage devices
I could find. Also for fun and to learn are some more, are good reasons to mess arround with this. One last
great advantage of this is you can have all configuration stored on one machine. Less running arround to resolve
software issuse.
Server Side:
Your server will need to do a couple of things. Typically it hosts DHCP (dynamic host configuration protocol).
If you said "I already have dhcp provided by my router!". This will not work. As you most likely cant configure
path for the network bootstrap program. Also there is a tftp which needs to be set up. This tftp hosts the kernel
whatever else you decide to put there. The PXE firmware usually asks for this network bootstrap program. Porteus
has all of this taken care of for us. When you select the pxeboot at the bootmenu. The boot option will configure
all of this for you.
Client side:
You needed a simple "pxe boot disk" in the past to do the PXE-boot a computer. Now most motherboards with integrated
network adapters allow for you to boot using the network adapter. You can find out how to enable network booting in
the motherboard manual, that usually comes with the computer. If not just scan around in the bios settings. You will
be looking for two things one says "Enable Network Boot:" with a enable/disable switch. It might be a little different
on the wordage. This needs to be enabled. Then you go to the boot options. Now that network boot is enabled you can
see it in the list with cdrom, floppy, and harddrive. Now we put it as the #1 boot option,(save and exit) then restart
your computer. You could also get a network adapter that, has this feature. If so you will need to set all the boot options
in the bios to pass or disable all of them. So the bios will pass the boot to the rest of the hardware in your computer.
Sometimes the network bootable Ethernet adapter can be seen by the bios and will give you the option to select it in the
boot options. Once you have it selected for booting from the network device. Make sure it is pluged into the network
then start it up. If your computer doesn't have the network boot option, check out http://etherboot.org . This is a
wonderful resource on non proprietary pxe roms.
Note:
I wrote this as a small general overview, as I am very buisy. If you have a specific question regarding this topic feel free to ask
here. I will answer to the best of my ability. Also the first time I ever put together a pxe server I was running an open-mosix
cluster. All my clients were just motherboard, cpu, ram, and power supply. After the bios's on those clients were configured I
did not have any need for a monitor keyboard or any other device attached. My pxe server was also running an open-mosix
kernel and I was able to use the cpu's and ram of all clients as if they existed within the server.
Short and simple definition this PXE allows us to boot the computer over the network not requiring
harddrive nor cdrom. You can do this with as few as 2 computers (1 server, 1 client), or as many as
can get your hands on.
Reasons for PXE booting:
$43.99 8 gb ssd
$14.99 40 gb ultra ata
$17.94 39 gb sata
$4 to $20 cdrom device
These prices are from pricewatch night of June 11, 2011.
So if we are setting up a network with 101 computers(1 server, 100 clients) we could potentially save
(100 X (cost of harddrive)) + (100 X (cost of cdrom)). And those were the cheapest data storage devices
I could find. Also for fun and to learn are some more, are good reasons to mess arround with this. One last
great advantage of this is you can have all configuration stored on one machine. Less running arround to resolve
software issuse.
Server Side:
Your server will need to do a couple of things. Typically it hosts DHCP (dynamic host configuration protocol).
If you said "I already have dhcp provided by my router!". This will not work. As you most likely cant configure
path for the network bootstrap program. Also there is a tftp which needs to be set up. This tftp hosts the kernel
whatever else you decide to put there. The PXE firmware usually asks for this network bootstrap program. Porteus
has all of this taken care of for us. When you select the pxeboot at the bootmenu. The boot option will configure
all of this for you.
Client side:
You needed a simple "pxe boot disk" in the past to do the PXE-boot a computer. Now most motherboards with integrated
network adapters allow for you to boot using the network adapter. You can find out how to enable network booting in
the motherboard manual, that usually comes with the computer. If not just scan around in the bios settings. You will
be looking for two things one says "Enable Network Boot:" with a enable/disable switch. It might be a little different
on the wordage. This needs to be enabled. Then you go to the boot options. Now that network boot is enabled you can
see it in the list with cdrom, floppy, and harddrive. Now we put it as the #1 boot option,(save and exit) then restart
your computer. You could also get a network adapter that, has this feature. If so you will need to set all the boot options
in the bios to pass or disable all of them. So the bios will pass the boot to the rest of the hardware in your computer.
Sometimes the network bootable Ethernet adapter can be seen by the bios and will give you the option to select it in the
boot options. Once you have it selected for booting from the network device. Make sure it is pluged into the network
then start it up. If your computer doesn't have the network boot option, check out http://etherboot.org . This is a
wonderful resource on non proprietary pxe roms.
Note:
I wrote this as a small general overview, as I am very buisy. If you have a specific question regarding this topic feel free to ask
here. I will answer to the best of my ability. Also the first time I ever put together a pxe server I was running an open-mosix
cluster. All my clients were just motherboard, cpu, ram, and power supply. After the bios's on those clients were configured I
did not have any need for a monitor keyboard or any other device attached. My pxe server was also running an open-mosix
kernel and I was able to use the cpu's and ram of all clients as if they existed within the server.