Re: Software RAID efficiency: Disks vs partitions

Hi,
> I am not sure this logic should be true, especially if the partitions
> are on a single disk. The number of read operations is hardware
> dependent, and scales linearly with number of hard-disks. - which is
> why one looks at stripping across multiple smaller disks to get faster
> concurrent access.
You are mostly right , its not just read but both read and write operations
which will scale depending on hardware ports/channels/disks.

Now in scenario where single partition spans whole disk there is no 
difference
between disk or partition. In a scenario where single physical disk
has multiple partitions, that will be less efficient.

In fact its best practice to partition the disk in a single partition 
and then
use that partition for raid. This is because disk between different vendors
or even different batches of same manufacturer can have slight difference
in available sector, which can create problem when you have to actually 
recover
from a hardware failure.

rgds
vivek

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