[dundee] ELF yourself encryption

[Andrew Clayton]

On Fri, 19 Jun 2009 15:26:00 +0000 (GMT), Lee Hughes wrote:

> I've been looking at linux raid 1 performance, i.e two driver,
> mirrored.
> 
> Seems that I saw something I was not familiar with 
> 
> check dis
> 
>   mdadm --create /dev/md2 --chunk=256 -R -l 10 -n 2 -p
> f2 /dev/sda2 /dev/sdb2
> 
>   mkfs -t ext3 /dev/md2
> 
>    RAID type      sequential read     random read    sequential
> write   random write Ordinary disk       82
> 34                 67                56 RAID0
> 155                 80                 97                80
> RAID1               80                 35
> 72                55 RAID10,n2           79
> 56                 69                48 RAID10,f2
> 150                 79                 70                55
> 
> 
> from http://linux-raid.osdl.org/index.php/Performance
> 
> but the performance is double? what gives..
> 
> I always thought that raid-1 gave a read performance increase?
> i.e it would read block in alternative drives?

I think what RAID 1 in terms of read gives you is more bandwidth.
Multiple discs can be at the same time, but only at the speed of a
single disk.

Andrew