> I have several questions: > > (1) Does this problem only exists in 3ware ide raid adaptor? > We test SCSI > too, it is much faster. > If it is 3ware's driver problem, scsi raid should have the same > problem. > (2) Has 3ware fixed this problem yet? They claim they support linux. Not sure about these as I have no experience with the 3ware cards > (3) One solution is to setup 3ware in jbod mode and use linux > software-raid. > what percentage of CPU used if using software-raid? It > might cost too > much CPU power > without using hardware raid. I just setup a 26 disk software RAID10 array on Linux and it has put a minimal load on the CPU's (my box is a Dell PowerEdge 6600 with quad Xeon 1.4GHz with HT enabled). I will be moving this box to a 52 disk software RAID10 setup as soon as I finish testing some kernel patches. I can recommend software RAID on Linux without hesitation. The kernel developers have done a great job with MD. > (4) Other than 3ware, is there any better raid card > supported by linux? > We moved from hardware to software RAID because we couldn't find a hardware card that gave us the performance that we wanted. I have the 52 disk RAID10 array described above setup on some test hardware at work and tiobench, with 4 threads and 32KB blocks shows 515MB/s sequential reads (ext3 default journaling mode). And as I said earlier, the load on the CPU's is minimal in my setup (OLTP and batch database processing). > I appreciate your guys help > > > Donghui Wen > > - > To unsubscribe from this list: send the line "unsubscribe > linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
