RAID1 and load-balancing during read

[Dimitrios Apostolou <jimis@gmx.net>]

Hello list, 

I just created a RAID1 array consisting of two disks. After experiments with 
processes *reading* from the device (badblocks, dd) and the iostat program, I 
can see that only one disk is being utilised for reading. To be exact, every 
time I execute the command one of the two disks is being randomly used, but 
the other one has absolutely no activity. 

My question is: why isn't load balancing happening? Is there an option I'm 
missing? Until now I though it was the default for all RAID1 implementations. 
Even md man page mentions in the RAID1 section: 

  The driver attempts to distribute read requests across all devices to 
maximise performance.


Thanks in advance, 
Dimitris