I have a server that was previously setup with Software RAID1 under CentOS 5.5 (/dev/sda
and sdb
). I added two additional drives to the server and was attempting re-install CentOS. The CentOS installer sees the 2 new drives fine (sdc
and sdd
), however it does not see the the two original drives sda and sdb as individual drives. Instead it only shows Drive /dev/mapper/pdc_... (Model: Linux device-mapper)
. Basically what I need to do is strip all RAID configurations off these drives and allow the installer to see them as individual physical disks.
I've tried pulling all the drives except one of the original ones, installing a minimal CentOS and running dmraid -r -E
, but it still sees the old RAID partition. None of the CentOS install options (remove previous partitions, etc.) seem to work.
Best Answer
It is an old thread but it ranks high on Google so many people read it and it needs to be updated.
The "correct" way would be to use
mdadm
with--zero-superblock
.man mdadm
The
dd
method withbs=<block size>
works also but one needs to be careful because not all superblocks are written to the beginning of the disk - some are written to the end of the disk.Update : rather use gdisk for wiping than any other method
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