Re: [Nolug] NAS

On 2010-04-10 22:32, John Souvestre wrote:
> Hi Shane.
>
>
>
> It depends on what you do most – read or write. It also depends on the
> size of the data blocks you are reading. For small blocks the disk
> access time is important and being able to get all of the data from just
> one drive access (Raid 1) is a big advantage. Indeed, with Raid 1 you
> can get all of the data from either drive, thus allowing you to overlap
> reads.
>

Note also that there are two kinds of orthogonal reads and writes:
length (short, long) and "direction" (sequential and random).

BITD (back in the day) RAID5 was faster than RAID1 in long
sequential reads because of parallelism (lots of disks and lots of
controllers) but RAID1 was faster at short reads and random short.
(Random long doesn't really make sense.)

Nowadays with capacities so enormous, it's hard to say what the
performance of SATA drives would be.

-- 
Dissent is patriotic, remember?
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