Miguel Medalha wrote:
>
>> have raid 0 and raid1 on the same drive isn't going to gie you anything
>> since the raid 1 will "slow" the other raids down.
>>
>
> You are assuming that both arrays will always be concurrently accessed
> but that may not be the case.
> More yet: the configuration may have been studied in such a way that
> concurrent access is rarely the case.
If you only have 2 drives there's not much you can do to avoid
concurrent access. The killer is head seek time - if you have your only
2 drives tied together in any kind of raid and the head needs to be in 2
places at once it doesn't matter much how you laid out the partitions.
Reads can be sort-of independent on raid1 but writes make both seek to
the same place.
--
Les Mikesell
lesmikesell at gmail.com