PXE booting, remote diskless booting, SCSI-on-IP booting

[scalar]

This may be considered a cheat of sorts because while it can work to silence your hard drive, it does so only by moving your system's hard drives out of the room.... WAY out of the room, as in, down the hall, perhaps in the basement, perhaps in another building.


The key here is Gigabit Ethernet and the Preboot Execution Environment (PXE). Very soon there will be a strange new option, known as SCSI on IP or just iSCSI.

Gigabit Ethernet provides speeds up to 125 megabytes per second, which far outstrips the speed of most any consumer hard drive. Additionally, standard CAT5E cable can carry this signal 200 meters without loss of quality.

PXE is a special option on some motherboards and LAN cards. Typically it is used as a way for a computer to start up using a boot image located on a network server, to perform actions prior to normal IDE/SCSI system startup. But it can also be used to boot a full operating system on the computer without a hard drive or flash card.

Gigabit ethernet is sufficiently fast that some people are talking about a new SCSI disk interface standard that allows servers to access data over ethernet rather than IDE, SCSI, USB, or firewire cables. This new iSCSI standard was just completed last winter, and Microsoft has apparantly written the first driver for it in June 2003.

The catch to all this is that you need another computer somwhere else that acts as a file server for your data, and is fast enough to deal with the processing needs of getting data off a hard drive and stuffing it into the gigabit pipe. (At least 1gHz may be needed on this server)

iSCSI remote-boot links

Mar 2003 - Microsoft to add iSCSI support to Windows
Apr 2003 - Let the iSCSI games begin
May 2003 - iSCSI and Microsoft make a potent combination

IBM iBoot - Remote boot over iSCSI


PXE diskless booting links

Diskless remote booting for Windows 2000/XP

Remote Boot of Windows 95 from OS/2 Warp server

Remote Boot of Windows ME from OS/2 Warp server

Using PXE to install Windows 98/NT/2000

PXE booting BSD/OS

PXE booting SysLinux

PXE booting Solaris


-Scalar

[Jan Kivar]

Gigabit Ethernet provides speeds up to 125 megabytes per second

Theoretically, that is. Getting more than 30 MB/s is very good, I've seen speeds that are around 15-20 MB/s. Jumbo frames must be supported. Using a Gbit NIC will use nearly all PCI resources. CSA (as in some i865/i875P boards) could help here.

But You don't "want" STR, You'd want super-fast seeks. (See here for a discussion...)

There was great discussion @ StorageReview.com about this (it was called elSCSI, and isn't really the same thing, but the base idea is similar). Too bad that the project was suspended.

Cheers,

Jan

[scalar]

Well, it's much the same with ATA-133. The drive mechanism and onboard controller typically cannot sustain the full 133 rate for any length of time either, and the actual continuous read/write rate may only be in the 10-20 megabytes/sec range.

What I'm saying is that the performance you'd experience with the coming iSCSI or PXE on gigabit Ethernet would be virtually identical to local ATA-133 IDE performance, but with the advantage that the drives can be moved up to 200 meters away with no loss in your system's performance.

-Scalar

[al bundy]

...What I'm saying is that the performance you'd experience with the coming iSCSI or PXE on gigabit Ethernet would be virtually identical to local ATA-133 IDE performance, but with the advantage that the drives can be moved up to 200 meters away with no loss in your system's performance.

-Scalar

This sounds really interesting, especially for streaming DVD over ethernet...

[Jan Kivar]

Well, it's much the same with ATA-133. The drive mechanism and onboard controller typically cannot sustain the full 133 rate for any length of time either, and the actual continuous read/write rate may only be in the 10-20 megabytes/sec range.

What I'm saying is that the performance you'd experience with the coming iSCSI or PXE on gigabit Ethernet would be virtually identical to local ATA-133 IDE performance, but with the advantage that the drives can be moved up to 200 meters away with no loss in your system's performance.

-Scalar

It would be interesting to build a computer without any drives. We are still not there, but iSCSI could help a bit. The problem here is that You could do it with FireWire (or even USB2 ), but MS doesn't offer boot-time drivers. Most computers have the capability (in BIOS) to boot from USB(2), but there's no support from the OS. Floppy emulation works though...

Cheers,

Jan