From: Iustin Pop <iusty@k1024.org>
There are many questions on the mailing list about the RAID1 read
performance profile. This patch adds a new paragraph to the RAID1
section in md.4 that details what kind of speed-up one should expect
from RAID1.
Signed-off-by: Iustin Pop <iusty@k1024.org>
When adding new disk to an array, don't reserve so much bitmap
space that the disk cannot store the required data. (Needed when
1.x array was created with older mdadm).