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.