Re: databases and RAID ...

Peter Eisentraut wrote:

>Tom Lane writes:
>
>
>
>>Is there any rhyme or reason to the various "RAID n" designations?
>>Or were they just invented on the spur of the moment?
>>
>>
>
>The paper that introduced the term RAID used a numerical classification
>for the various schemes.  (So I guess the answer is yes.)  The traditional
>levels are:
>
>0  Nonredundant
>1  Mirrored
>2  Memory-style ECC
>3  Bit-interleaved parity
>4  Block-interleaved parity
>5  Block-interleaved distributed parity
>[Hennessy & Patterson]
>
>There are also other levels.  One poster talked about RAID 10 which
>appears to be a mirrored RAID 5.
>
>
>
No Raid 10 is Raid 1 + 0 its strong points are faster writes but slower
reads.

- Bill