>
> i have set up an md (raid1) device. it has two hard disks.
>
> Something has gone bad on the disks, such
> that whenever I do a raidstart or mkraid, it
> says
> raid set md0 not clean. starting background reconstr.. ..
>
> what can I do to clean my md device.
If the raid device isn't stopped correctly it will be dirty and requires
a resync the next startup. A reconstruction is also done when the array
is initially created. This reconstruction step is actually unnecessary
for RAID-1, but is vital for RAID-5; but the raid driver does it anyway.
Also, you must allow a resync to completely finish before stopping the
array; otherwise, the array will start all over again the next time it
is started.
> mkraid --really-force also is not helpful .
> i have tried destroying both hard disk partitions using fdisk
> and doing a clean raid setup, still it starts the background
> reconstruction.
>
> also what is the command to do a low level format of the harddisk
> in linux?
There is no built in command to format a disk. You can easily zero out
the data by doing a 'dd </dev/zero >/dev/sda'. If you are using scsi,
then there is a scsiformat utility with the scsiinfo package, but this
may need fiddling to compile.
<>< Lance.
