[CentOS] SATA vs. SAS

On Wednesday 22 August 2007, Bowie Bailey wrote:
> Peter Arremann wrote:
> > On the other hand, data reliability is another issue. We have tons of
> > sata based disk arrays and have had no issues yet (because our systems
> > are all on UPS and multiple circuits) but if you don't have
> > infrastructure like that, you are more likely to lose data on a sata
> > based system...
>
> Why do you say that SATA arrays are less reliable?  I have used both
> SATA and SCSI raid and have had drive failures on both.  Recovery from
> the failures seems to be more a matter of the raid implementation than
> the interface type.


Not all drive support cache flushes and handle them correctly - even with NCQ. 
Same for some older controllers also have some issues too. 
Doesn't show up as a hardware error but as filesystem inconsistency after a 
crash.  

As I wrote, we haven't had issues yet either. But sun, sgi, ibm and others are 
fairly conservative  - sun says they still only ships 500GB disks in their 
x4500 for that reason. 

Peter.