> I've read a lot of different reports that suggest at this point in time, > kernel software raid is in most cases better than controller raid. > Let me define 'most cases' for you. Linux software raid can perform better or the same if you are using raid0/raid1/raid1+0 arrays. If you are using raid5/6 arrays, the most disks are involved, the better hardware raid (those with sufficient processing power and cache - a long time ago software raid 5 beat the pants of hardware raid cards based on Intel i960 chips) will perform.
I have already posted on this and there are links to performance tests on this very subject. Let me look for the post. > The basic argument seems to be that CPU's are fast enough now that the > limitation on throughput is the drive itself, and that SATA resolved the > bottleneck that PATA caused with kernel raid. The arguments then go on > Complete bollocks. The bottleneck is not the drives themselves as whether it is SATA/PATA disk drive performance has not changed much which is why 15k RPM disks are still king. The bottleneck is the bus be it PCI-X or PCIe 16x/8x/4x or at least the latencies involved due to bus traffic. > to give numerous examples where a failing hardware raid controller > CAUSED data loss, where a raid card died and an identical raid card had > to be scrounged from eBay to even read the data on the drives, etc. - > problems that apparently don't happen with kernel software raid. > > Buy extra cards. Duh. Easy solution for what can be a very rare problem. _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
