With regards to your message at 08:31 PM 10/17/02, Gregory Leblanc. Where you stated: >Err, so are you saying that a single sequential I/O is slower on RAID >1 when compared with a single disk? That doesn't make a lot of >sense. There -are- instances where parallel I/O is required. In >these cases, any RAID-1 should be much faster than a single disk, as >should RAID 10. I'm not sure that RAID 5 should give a similar >benefit, but given the cost of disks, I don't care about RAID 5. Of course RAID1 should be slower. We are doing more WORK! We have to generate two writes, and manage them and the RAID. With a single disk we are doing much less, and there is _much_ less overhead. In an ideal world RAID10 will gain us back the loss because of the RAID0 element which DOES gain us some performance back. But even then the CPU load will be much more, as we are still writing more data. With our best regards, Maurice W. Hilarius Telephone: 01-780-456-9771 Hard Data Ltd. FAX: 01-780-456-9772 11060 - 166 Avenue mailto:maurice@harddata.com Edmonton, AB, Canada http://www.harddata.com/ T5X 1Y3 Ask me about NAS and near-line storage - 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
