Neil Hello . I have a performance question. I am using raid5 stripe size 1024K over 4 disks. I am benchmarking it with an asynchronous tester. This tester submits 100 IOs of size of 1024 K --> as the stripe size. It reads raw io from the device, no file system is involved. I am making the following comparsion: 1. Reading 4 disks at the same time using 1 MB buffer in random manner. 2. Reading 1 raid5 device using 1MB buffer in random manner. I am getting terrible results in scenario 2. if scenario 1 gives 120 MB/s from 4 disks, the raid5 device gives 35 MB/s . it is like i am reading a single disk , but by looking at iostat i can see that all disks are active but with low throughput. Any idea ? Thank you. -- Raz - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
