Hi, Thank you - it looks like it worked. [root@ion ~]# mdadm --examine --verbose --scan ARRAY /dev/md/0 level=raid5 metadata=1.2 num-devices=6 UUID=e6595c64:b3ae90b3:f01133ac:3f402d20 name=ion:0 devices=/dev/sdg1,/dev/sdf1,/dev/sde1,/dev/sdd1,/dev/sdc1,/dev/sdb1 Will run an fsck just in case. Cheers, // Mathias On 29 October 2010 21:44, Neil Brown <neilb@xxxxxxx> wrote: > On Fri, 29 Oct 2010 15:18:09 +0100 > Mathias BurÃn <mathias.buren@xxxxxxxxx> wrote: > >> Question 3: Before I created this RAID5 array I did a quick RAID0 test >> array just for fun, using 2 full devices (not partitions). Now I have >> this: >> >> mdadm Â--examine --verbose --scan >> ARRAY /dev/md/raid0-test level=raid0 metadata=1.2 num-devices=2 >> UUID=b84cc081:1ae27b49:d5ae466c:377ba300 name=ion:raid0-test >> Â Âdevices=/dev/sdf,/dev/sdb >> ARRAY /dev/md/0 level=raid5 metadata=1.2 num-devices=6 >> UUID=e6595c64:b3ae90b3:f01133ac:3f402d20 name=ion:0 >> Â Âdevices=/dev/sdg1,/dev/sdf1,/dev/sde1,/dev/sdd1,/dev/sdc1,/dev/sdb1 >> >> Is it safe to erase the raid0-test superblocks on device /dev/sdb and >> /dev/sdc or will it interfere with my RAID5 array (which is lying on >> top of partitions) ? > > It should be safe to > Âmdadm --zero-superblock /dev/sdf /dev/sdb > > As you have 1.2 metadata, that info will be 4K from the start of the device. > Depending on how you partitioned the devices, that is either in dead space > between the partition table and the first partition, or it is in dead space > in the first partition just before the md metadata. > > So the old metadata is still visible, creating the new arrays clearly didn't > over-write it, so they don't really care what is there... > > That statement isn't 100% general. A block in the data area of the new array > could be unchanged by creating an array, yet changing it could still corrupt > parity. ÂHowever you can be certain that the metadata for a whole-device > array does not lie in the data area for a partitioned array of the same > metadata type. > > NeilBrown > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
