> On Thu, Nov 30, 2006 at 10:53:26PM +0100, Matus UHLAR - fantomas wrote: > > > > I did not want to mention this, because: > > > > - software RAID-1 has bus overhead (the same data have to be transferred > > multiple times to multiple drives, so writing may be twice as slow) On 30.11.06 17:00, Roberto C. Sanchez wrote: > This is only true if you use IDE and also put the mirrored pair on the > same channel (which would be incredibly foolish). Under every other > conceivable scenario, the system is smart enough to do both writes > simultaneously since they will be going difference places.
but the data will still be fetched two times from memory to a controller(s) > > - software RAID-1 has high CPU and bus overhead in case of resyncing after > > disk outage (hw raid does that itself) > > Huh? I have built lots of RAID one systems and seen many of them > resync. They do have high I/O overhead (naturally, since it is a > resync). However, I have never seen one produce high CPU overload. I should write "higher CPU overload" > I suppose if you forgot to enable DMA on your drives, or somehow managed > to disable it (it is enabled by default), then you might see high CPU load > during resync. But then, you would see high CPU load for anything that > does any significant amount of I/O. -- Matus UHLAR - fantomas, [EMAIL PROTECTED] ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. I just got lost in thought. It was unfamiliar territory. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
