What is LBA48 ? I have a western digital 200GB IDE hard drive (WD2000JB) and I can only partition about 137GB. After playing around for a while I found that I need "LBA48 support" to be able to partition the whole drive.
however I cant seem to figure out exactly what LBA48 is and how to use it. Is it a driver that I need to compile into my kernel? is it a shared lib? is it a property of my hardware and if I want to use it I would need to buy the appropriate piece of hardware? is it some fundamental part of the kernel that has already been compiled into the kernel and all I have to do it turn it on?
Any info on LBA48 would be helpful. And by the way I have a slackware 9.1 Distribution with a 2.6.4 kernel I compiled.

Regards
Aaron Saxton

LBA48 support usually refers to your BIOS.

If that is the case you need to either update your BIOS (if possible) or get a new motherboard.

48-bit Logical Block Addressing (LBA) extends the capacity of IDE ATA/ATAPI devices beyond the limit of 137.4 GB. This limit applies to IDE ATA/ATAPI devices only and not to SCSI interface devices. The original design specification for the ATA interface only provided 28-bits with which to address the devices. This meant that a hard disk could only have a maximum of 268,435,456 sectors of 512 bytes of data thus limiting the ATA interface to a maximum of 137.4 gigabytes. With 48-bit addressing the limit is 144 petabytes (144,000,000 gigabytes).

The kernel, motherboard BIOS and the IDE controller needs to support LBA48. AFAIK the 2.6 kernel shouldn't have a problem with LBA48.

Thanks a lot for the help so far. I have been having problems with corrupted data for months now and this information has helped me understand why it is being corrupted.
However, I still have some issues. I have a a7a266 motherboard with a ALI M1535D+ IDE chip set and from what I can find ALI doesn't support LBA48 while in DMA mode, but it will if I drop down to PIO.
After doing some more poking around I found that when I compile the kernel I can tell it to use DMA by default or not. I told it not. but my dmesg still says that it's using DMA for the 200GB hard drives.... I then found how to tell my BIOS not to use DMA.... alas, dmesg still tells me that DMA is being used for my 200GB drives!
Where exactly can I turn off DMA?!