[CentOS] Infrastructure HELP!

Thu Oct 29 21:07:59 UTC 2009
Rainer Duffner <rainer at ultra-secure.de>

Am 29.10.2009 um 21:50 schrieb Curt Mills:

> On Thu, 29 Oct 2009, Matt wrote:
>
>> What is the cheapest SATA hardware raid card I can get at newegg.com?
>> Seems like most turn out not to be true hardware raid that I have
>> found and will not run on CentOS 4.8 without a great deal of grief.
>
> Not a direct answer to your question, but be careful of SATA drives.
>
> As I understand it SAS drives (Serially Attached SCSI) are designed
> to handle server duty (multiple processes stepping the head 24/7),
> whereas SATA drives (Serially attached ATA) are not.  SATA drives if
> used in servers will fail prematurely.  They're great/cheap for home
> use though.
>
> I've also heard that SATA-2 drives are more like SAS or SCSI drives
> in this respect, as in they're designed for server duty.
>
> I probably heard the above on this very list in the past.
>
> Can someone confirm or deny?  Making me look like a fool is ok, I'm
> used to it.  ;-)


There are server-grade SATA2 drives.
They're usually a bit louder but are designed to run 24/7. They can  
also deal better with vibrations.
Desktop-drives are designed to run for maybe 10hours a day - but they  
can achieve more spin-up/spin-down cycles than server-grade SATA-drives.

SAS drives deliver more IOP/s.
You waste a lot of SATA-capacity to achieve the same amount of IOP/s.

Really, for the stuff he wants to do, he does not need a lot of I/O -  
IMO.

Without knowing what kind of social networking site he has in mind,  
I'd say that the traffic of 5000 users (of course, not 5000  
simultaneous users) can easily be handled by a single server with  
enough RAM.





Rainer