Linux Software Raid 1 Recovery Question

[Kent Borg]

On Wed, Sep 25, 2002 at 05:09:52PM -0400, Derek Atkins wrote:
> It does look like multiple MBRs were installed..  The numbering
> makes perfect sence to me:
> 
>  0301 == hda1  03h == 03d == MAJOR(HDA)
>  1601 == hdc1  16h == 22d == MAJOR(HDC)

I think there are two things here.  First, the MBR needs to describe
both disks.  Second, an MBR like that needs to be put on both disks.

Running at a higher verbosity, it looks to me like everything
(describing both disks) is getting written to only one disk.  Note the
"Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders".  That is
the geometry of the drive on /dev/hda, the other drive is the
identical part number but claims to have 116336 cylinders.  Here is
the "-v -v -v" output:

   # lilo -v -v -v
   LILO version 21.4-4, Copyright (C) 1992-1998 Werner Almesberger
   'lba32' extensions Copyright (C) 1999,2000 John Coffman
   
   boot = /dev/hda, map = /boot/map.0301
   Reading boot sector from /dev/hda
   Merging with /boot/boot.b
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Secondary loader: 11 sectors.
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Mapping message file /boot/message
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Message: 46 sectors.
   Boot image: /boot/vmlinuz-2.4.18-10
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Setup length is 10 sectors.
   Mapped 2035 sectors.
   Mapping RAM disk /boot/initrd-2.4.18-10.img
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   RAM disk: 262 sectors.
   Added linux *
       <dev=0xc0,hd=0,cyl=107,sct=191>
       "ro root=905 BOOT_FILE=/boot/vmlinuz-2.4.18-10"
   /boot/boot.0300 exists - no backup copy made.
   Map file size: 16384 bytes.
   Writing boot sector.
   boot = /dev/hdc, map = /boot/map.1601
   Reading boot sector from /dev/hdc
   Merging with /boot/boot.b
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Secondary loader: 11 sectors.
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Mapping message file /boot/message
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Message: 46 sectors.
   Boot image: /boot/vmlinuz-2.4.18-10
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   Setup length is 10 sectors.
   Mapped 2035 sectors.
   Mapping RAM disk /boot/initrd-2.4.18-10.img
   Device 0x0301: BIOS drive 0x80, 255 heads, 7299 cylinders,
                  63 sectors. Partition offset: 63 sectors.
   RAM disk: 262 sectors.
   Added linux *
       <dev=0xc0,hd=0,cyl=107,sct=227>
       "ro root=905 BOOT_FILE=/boot/vmlinuz-2.4.18-10"
   /boot/boot.1600 exists - no backup copy made.
   Map file size: 16384 bytes.
   Writing boot sector.
   # 



-kb