Build Your Own SATA Hard Drive Switch

Mikey Win writes "ExtremeTech shows us a cool hardware hack that allows multiple operating system to boot without dealing with any tedious BIOS setup changes. How? By building your own SATA hard drive switch. The result? You can expect a longer hard drive life span, power supply load reduction, and partitions protected from becoming overwritten or corrupted."

Signal But no Power == BAD?

[Anonymous Coward]

Something tells me this is probably not a good idea.

Having a signal connected to the hard drive, and no power applied, at least in a traditional TTL or CMOS circuit, is not a good idea.

Since SATA is based on LVDS, this might not suffer from the typical CMOS or TTL problems, but I would investigate it a bit further.

Intelligent Switch Would be Better

[wkk2]

An active switch that could select a drive and optionally block write commands would even be better. Then you could make an image and turn on write protection.

Re:How is this a SATA switch?

[gabebear]

I was excited about building an active SATA multiplexer... but this is just dumb. I did something similar a long time ago with IDE drives; instead of powering one drive down I had the switch attached to jumper positions so that the switch controlled master/slave.

Sata Hub (but not a switch)-> http://www.cooldrives.com/sahub5muussi.html [cooldrives.com]

Re:If I need to access both drives from either OS?

[ILikeRed]

It would be a nice feature on a motherboard to have four shunt pin switches that determines the first boot drive priority from the four SATA drives. They could ship the motherboard with just the drive 0 shunted, but then you could get a four position switch that would shunt the different pins. It would not have any effect if turned when the computer is on, but could signal the bios to the top boot priority during post (and just have the bios default to 0 if either multiple or no pins are shunted.)

Re:How is this a SATA switch?

[Fourier]

I've helped to guide a bunch of SATA boards from prototype to product. From personal experience, I can tell you that a switch put together "half-decently" is very likely to result in unreliable SATA communication.

Re:Grub

[Pentium100]

I don't know if this works with grub, but it worked with lilo when I tried.

1.Install the linux bootloader to the first sector of the linux partition.
2.Export that sector to file (dd if=/dev/hda6 of=linux.bin bs=512 count=1) where /dev/hda6 is your linux partition.
3.Copy the linux.bin file to your Windows C: drive.
4.Open your C:\boot.ini file and add C:\linux.bin="Linux" after the last line.

You can now use Windows bootloader to choose between Windows and Linux.