Re: LILO with root-raid nightmare - please help.

[drbob <drbob@gmx.co.uk>]

Thanks for the advice, I managed to get the system booting off either 
disc without further swapping of the drives around though. I set 
"raid-extra-boot=mbr-only" in lilo.conf. This forces lilo to rewrite the 
mbr of each disc in the raid1 array and not to the first sector of the 
raid1 partition. The default since version 22.0 has been to only write a 
boot record to the first sector of the raid1 partition, which for some 
reason didn't work for me. I can now boot from either drive and so am 
happy. I still don't know why lilo wouldn't write a boot record to my 
raid partition, but things seem to work ok like this. Thanks for all 
your help.

From the relevant part of the lilo man page:

raid-extra-boot=<option>
             This  option  only  has  meaning for RAID1 installations.  
The <option> may be specified as
             none,   auto,   mbr,   mbr-only,   or   a   
comma-separated   list   of   devices;    e.g.,
             "/dev/hda,/dev/hdc6".  Starting with LILO version 22.0, 
the boot record is normally written
             to the first sector of the RAID1 partition.  On PARALLEL 
raid sets, no other  boot  records
             are  needed.   The  default  action  is auto, meaning, 
automatically generate auxilary boot
             records as needed on SKEWED raid sets.  none means 
suppress  generation  of  all  auxiliary
             boot  records.   mbr-only  suppresses  generation  of a 
boot record on the raid device, and
             forces compatibility with versions of LILO  earlier  than  
version  22.0  by  writing  boot
             records  to  all  Master Boot Records (MBRs) of all disks 
which have partitions in the raid
             set. mbr is like mbr-only except the boot record on the 
RAID parition  is  not  suppressed.
             Use  of an explicit list of devices, forces writing of 
auxiliary boot records only on those
             devices enumerated, in addition to the boot record on the 
RAID1 device. Since  the  version
             22  RAID1  codes will never automatically write a boot 
record on the MBR of device 0x80, if
             such a boot record is desired, this is one way to have it 
written. Use of mbr is the  other
             way to force writing to the MBR of device 0x80.


regards,

drbob