I've got a RAID1 array. I'm buying 4 more disks of equal size (they're the same model drives) and I'm trying to enumerate my options for a safe upgrade. Ideally they'll be one large ext3 volume.
Firstly, am I crazy? Do I really want to move software RAID1 to 5 or 6? Will I wish I never had? The machine is fairly powerful (an i7 with 12gigs of RAM) but will performance be significantly worse? Is R6 worse than R5?
I should add that there is nothing "running" of this disk - it's purely storage for a small network.
Step two: How do I do it? If I'm going for RAID6, is it best to create a new 6-disk RAID6 array in a failed state (ie 2 drives missing), copy the data across from the RAID1, break the RAID1 and add those disks to the RAID6?
I'm really keen for any feedback from mdadm users.