Page 1 of 1

CHS or LBA?

Posted: Sun Sep 29, 2002 4:44 pm
by KachiWachi
Hi Again...

I have a WD AC28400 8.4GB drive here...why would a BIOS prefer to set it up in CHS (LARGE) mode rather than in LBA mode? I mean this by using the *Auto Mode* and not using the *IDE Detection* screen, where it does pick LBA as the recommended setup.

If the drive was set up in CHS, then I changed the BIOS to LBA, would I lose the data on the drive?

Thanks as always...

Posted: Sun Sep 29, 2002 6:04 pm
by edwin
You wouldn't loose the data but you cannot read it either.

Can't quite think of a reason other than a buggy bios. Set it for LBA.

Posted: Sun Sep 29, 2002 6:11 pm
by Rainbow
I've seen that on some early Award v4.50 BIOSes.

Posted: Mon Sep 30, 2002 3:02 pm
by KachiWachi
Well, here's the story...

I had originally setup the drive on my girlfriends now defunct SuperMicro P5STE with an AMI BIOS (see other post on that) and it set it up as LARGE (why I don't know). So when I moved it over to her new(er) computer (Biostar M5ATC w/ patched BIOS from here), it also seemed to set it up as LARGE, but I couldn't see any data (as edwin mentioned). Well, I had been playing around with the 40GB and this guy attached to the motherboard (see other post) so I thought maybe something got corrupted somehow, and I set Norton NDD to work on it. Well, basically I didn't notice that NDD was showing the drive to be a 15.6GB HD and not an 8.4GB, and proceeded to let it try to *fix* things... BIOS was still reporting 8.4GB so why would I look??

UGH!!!

Well, to make a long story short, NDD *fixed* it alright...

So now I go and reformat the thing to start over...things seemed to go OK...so I reboot, it still detects LARGE, but the format didn't hold. So I do this 3 times...zip...so now I'm thinking her HD went bad. NDD was saying the Boot Record was all messed up, and that there were bad sectors on the drive. When it tried to repair it, NDD would crash with a runtime error.

Well, on a whim I decided to nuke (fdisk) the partition tables and really start over... As soon as I did that, and rebooted, the M5ATC then set it up in LBA. Is that information stored on the drive somewhere (whether it is setup in NORMAL, CHS, or LBA)?? After fdisk and format, things held and no bad sectors were found.

In any case, this will give me a clean start (yet again for her...lol).

Any thoughts on what happened?