[OSM-dev] 0.6 move and downtime (re-scheduled)

[Matt Amos]

On Fri, Mar 13, 2009 at 1:21 AM, Stefan de Konink <stefan at konink.de> wrote:
> Grant Slater wrote:
>> Summary:
>> 2x Intel Xeon Processor E5420 Quad Core
>> 32GB ECC (max 128GB)
>> 2x 73GB SAS 15k
>> 10x 450GB SAS 15k (expensive, but stupidly low latency)
>> IPMI + KVM
>
> Maybe a stupid question; but is your database server able to exploit the
> above configuration? Especially related to your processor choice.

yes.

> Now it is nice you put 32GB (extra expensive) memory in there, but most
> likely your hot performance would be far better with more (cheap) memory
> than more disks.

there's a good reason why we are using good quality server-grade
memory in the OSM server. would we like more memory - of course! thats
why grant has very sensibly left 8 slots free.

> At the time I wrote my paper on OSM Dec2008, there was
> about 72GB of CSV data. Thus with lets say 128GB you will have your
> entire database *IN MEMORY* no fast disks required.

in 8Gb kits? that would be *extra* expensive (about £8,680 according
to froogle).

> ...or are you actually moving from OS to Solaris to utilize those 10
> disks for your lets say less than 100G worth of geodata using them as
> duplicates in the pool [opposed to integrity duplicates]?

partly, yes. RAID10 uses a mixture of striping and mirroring to
increase performance without sacrificing reliability.

cheers,

matt