Обсуждение: Lower Random Access Time vs RAID 0 / 1

Hello

I plan to buy a new development server and I wonder what will be the best HD combination.

I'm aware that "best combination" also relay on DB structure and usage.
so lets assume, heavy duty large DB with mostly reads and heavy write actions from time to time ( updates / huge transactions ).

Here are the options:

One very fast 10K RPM SATA Western Digital Raptor 150GB HD.
  Pro: very low access time and generally 30% faster regarding mainstream HD.
  Con: Expensive.

2 mainstream 7.2K RPM SATA HD in RAID 0.
  Pro: fast transfer rate.
  Con: Access time is lowered as both HD has to sync for read / write ( true ? ).

2 mainstream 7.2K RPM SATA HD in RAID 1.
  Pro: can access parallely different files in the same time ( true ? ).
  Con: Slower at writing.

Random access benchmark:
http://www23.tomshardware.com/storage.html?modelx=33&model1=280&model2=675&chart=32

Will be happy to hear recommendations and ideas.

Thanks,
Miki

--
--------------------------------------------------
Michael Ben-Nes - Internet Consultant and  Director.
http://www.epoch.co.il - weaving the Net.
Cellular: 054-4848113
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1= a better HD comparison resource can be found at www.storagereview.com
http://www.storagereview.com/comparison.html

You will find that storagereview has better information on any and
all things HD than Tom's does.


2= DB servers work best with as many spindles as possible.  None of
your example configurations is adequate; and any configuration with
only 1 HD is a data loss / data corruption disaster waiting to happen.
In general, the more spindles the better with any DB.  The =minimum=
should be at least 4 HD's =dedicated= to the DB.  OS HD's are
independent and in addition to the 4+ DB HDs.


3= "heavy duty large DB with mostly reads and heavy write actions
from time to time ( updates / huge transactions )." Does not have
anywhere near the precision needed to adequately describe your needs
in engineering terms.
How big a DB?
What % of the IO will be reads?  % writes?
How big is a "huge transaction"?
Exactly what is the primary use case of this server?
etc.  We need =numbers= if we are going to think about "speeds and
feeds" and specify HW.


4= =seriously= consider HW RAID controllers like 3ware (AKA AMCC) or
Areca. with BB IO caches.


You've got a lot more work ahead of you.
Ron


At 05:08 AM 3/22/2007, Michael Ben-Nes wrote:
>Hello
>
>I plan to buy a new development server and I wonder what will be the
>best HD combination.
>
>I'm aware that "best combination" also relay on DB structure and usage.
>so lets assume, heavy duty large DB with mostly reads and heavy
>write actions from time to time ( updates / huge transactions ).
>
>Here are the options:
>
>One very fast 10K RPM SATA Western Digital Raptor 150GB HD.
>   Pro: very low access time and generally 30% faster regarding mainstream HD.
>   Con: Expensive.
>
>2 mainstream 7.2K RPM SATA HD in RAID 0.
>   Pro: fast transfer rate.
>   Con: Access time is lowered as both HD has to sync for read /
> write ( true ? ).
>
>2 mainstream 7.2K RPM SATA HD in RAID 1.
>   Pro: can access parallely different files in the same time ( true ? ).
>   Con: Slower at writing.
>
>Random access benchmark:

><http://www23.tomshardware.com/storage.html?modelx=33&model1=280&model2=675&chart=32>http://www23.tomshardware.com/storage.html?modelx=33&model1=280&model2=675&chart=32

>
>
>Will be happy to hear recommendations and ideas.
>
>Thanks,
>Miki
>
>--
>--------------------------------------------------
>Michael Ben-Nes - Internet Consultant and  Director.
><http://www.epoch.co.il>http://www.epoch.co.il - weaving the Net.
>Cellular: 054-4848113
>--------------------------------------------------