Reformatting hard disk.
in [Linux Hardware]
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From: john on 28 Jan 2008 12:08 After various experiments, including an attempt to install Windows 2000 (it failed) I can no longer boot from /dev/hda. I have reassigned /dev/hdb as my hard drive boot device in the bios. Now I want to do a low level format on /dev/hda and start all over. I have already tried the trick of using a DOS fdisk from a floppy to zero out the MBR: A: fdisk /mbr That may have made things worse, I don't know. There is a dd command that will zero out the mbr first block but I forget what the exact string is. Here are some specs on the drives from dmesg: hda: ST3250824A, ATA DISK drive hdb: Maxtor 6Y080P0, ATA DISK drive The /hda drive is a recent 250MB drive. Windows 2000 however sees it as a 133MB drive. When I try to use it in a normal manner as the boot device LILO gives me an L followed by series of 99 99 99 etc. Other than the booting problem the drive seems to operate OK. I can boot a partition on it and so on using either my LILO file on the second drive or an install cdr. I began having trouble after the failed Win 2000 install. I want to boot from it because it is my newest drive and I routinely buy a new drive every three years, retiring the oldest one to the junque box. This one has only been in service about one year. Any other suggestions appreciated. John Culleton
From: Shadow_7 on 28 Jan 2008 12:35 > Now I want to do a low level format on /dev/hda and start all over. I > have already tried the trick of using a DOS fdisk from a floppy to > zero out the MBR: > A: fdisk /mbr > That may have made things worse, I don't know. The newer windows method is fixmbr. Or something like that. > There is a dd command that will zero out the mbr first block but I > forget what the exact string is. dd if=/dev/zero of=/dev/hda count=1 bs=512 NOTE: fdisk /MBR does NOT zero out the MBR. I puts the windows stuff/bootloader into the MBR. With a zero'd out MBR, you cannot boot anything off of the drive until you run fdisk /MBR or fixmbr in windows, or install grub or lilo to the MBR. Granted that it's hard to run fdisk /MBR in windows when it requires you to reboot before you've had a chance to run it. Thank goodness for grub boot cd's and floppies. Also note that the partition table is also in that first 512 bytes, so you'll likely need to repartition it after running that dd command. > Here are some specs on the drives from dmesg: hda: ST3250824A, ATA DISK > drive > hdb: Maxtor 6Y080P0, ATA DISK drive > > The /hda drive is a recent 250MB drive. Windows 2000 however sees it as > a 133MB drive. There's a motherboard limitation on older boards that only recognizes about that much of a drive larger than that. Not much of a problem in linux as you can boot from it and use all of the drive in most cases. Just make sure your boot partition is in that first 133MB seen by the motherboard. In windows you're pretty much screwed and can only use 133MB of that 250MB drive. At least until you upgrade your motherboard and cpu, or bios. HTH
From: Grant on 28 Jan 2008 12:46 On Mon, 28 Jan 2008 09:08:23 -0800 (PST), "john(a)wexfordpress.com" <john(a)wexfordpress.com> wrote: >After various experiments, including an attempt to install Windows >2000 (it failed) I can no longer boot from /dev/hda. I have >reassigned /dev/hdb as my hard drive boot device in the bios. > >Now I want to do a low level format on /dev/hda and start all over. I >have already tried the trick of using a DOS fdisk from a floppy to >zero out the MBR: >A: fdisk /mbr >That may have made things worse, I don't know. Doesn't help linux :) > >There is a dd command that will zero out the mbr first block but I >forget what the exact string is. dd if=/dev/zero bs=512 count=63 of=/dev/hda Zeroes out the first cylinder, clears the partition table... I prefer to zero the entire drive for reuse, this also gives the drive a chance to remap any iffy sectors: dd if=/dev/zero bs=1M of=/dev/hda >The /hda drive is a recent 250MB drive. Windows 2000 however sees it >as a 133MB drive. You need winxp sp2 to get the LBA48 driver (LBA48 is how to address >128GiB), don't know if msft made a fix for win2k. >When I try to use it in a normal manner as the boot device LILO gives >me an L followed by > series of 99 99 99 etc. Forget to run lilo after rewriting /etc/lilo.conf? Grant. -- http://bugsplatter.mine.nu/
From: Anton Ertl on 28 Jan 2008 12:54 "john(a)wexfordpress.com" <john(a)wexfordpress.com> writes: >After various experiments, including an attempt to install Windows >2000 (it failed) I can no longer boot from /dev/hda. I have >reassigned /dev/hdb as my hard drive boot device in the bios. > >Now I want to do a low level format on /dev/hda and start all over. No need for a low-level format. > I >have already tried the trick of using a DOS fdisk from a floppy to >zero out the MBR: >A: fdisk /mbr >That may have made things worse, I don't know. You should also be able to use one of the Linux partition tools to repartition the drive. >There is a dd command that will zero out the mbr first block but I >forget what the exact string is. dd if=/dev/zero of=/dev/hda bs=64k count=1 should be sufficient. Actually the partition table has never been a problem in my experience, but sometimes I have had to erase the start of the partition (because, e.g., the md driver would ignore the partition type and just grab the partition). You can do that with a similar command, but use the partition device instead of /dev/hda). >>When I try to use it in a normal manner as the boot device LILO gives >me an L followed by > series of 99 99 99 etc. My guess is that you have the first stage of LILO in the MBR, but the rest has been overwritten. Just reinstalling LILO (maybe after installing a Linux distro) should fix that. - anton -- M. Anton Ertl Some things have to be seen to be believed anton(a)mips.complang.tuwien.ac.at Most things have to be believed to be seen http://www.complang.tuwien.ac.at/anton/home.html
From: john on 28 Jan 2008 16:33
On Jan 28, 12:46 pm, Grant <g_r_a_n...(a)dodo.com.au> wrote: > On Mon, 28 Jan 2008 09:08:23 -0800 (PST), "j...(a)wexfordpress.com" <j...(a)wexfordpress.com> wrote: > >After various experiments, including an attempt to install Windows > >2000 (it failed) I can no longer boot from /dev/hda. I have > >reassigned /dev/hdb as my hard drive boot device in the bios. > > >Now I want to do a low level format on /dev/hda and start all over. I > >have already tried the trick of using a DOS fdisk from a floppy to > >zero out the MBR: > >A: fdisk /mbr > >That may have made things worse, I don't know. > > Doesn't help linux :) > > > > >There is a dd command that will zero out the mbr first block but I > >forget what the exact string is. > > dd if=/dev/zero bs=512 count=63 of=/dev/hda > > Zeroes out the first cylinder, clears the partition table... > > I prefer to zero the entire drive for reuse, this also gives the drive a > chance to remap any iffy sectors: > > dd if=/dev/zero bs=1M of=/dev/hda > I am doing that as we speak (or write, actually.) It takes a long time. <snip> > >When I try to use it in a normal manner as the boot device LILO gives > >me an L followed by > > series of 99 99 99 etc. > > Forget to run lilo after rewriting /etc/lilo.conf? > No. But lilo might have gone to the wrong drive. In any case the work proceeds. Thanks to all who wrote. John C. |