MD3000i Performance below benchmarks?

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MD3000i Performance below benchmarks?

  • We have an MD3Ki with 450GB 15K RPM SAS drives. Using what we believe to be correctly configured MPIO on an isolated gigabit Cisco switch, we are only seeing about 78MB/s transfer rates. Reviews of the MD3Ki that I have seen have indicated closer to 120MB/s, and generally mention running the raid controllers in "active / active" mode. I can't seem to find any documentation on this mode. Does anybody have suggestions?

    Our iSCSI client is a Dell 1850, 8GB RAM, dual proc, win 2K3 64-bit, Intel 4-port gigabit card, and we are using "HD Tach" for testing.

    thanks,
    dave.
  • Many factors to performance.

    How many drives are in the array ?
    What RAID level are you testing ?
    What is the block size of the transfers from HD Tach ?
    What is the percentage of Read/Write mix in the test ?
    Is your 78MB/s transfer rate the reads or the rights, or both combined ?
    Is HD Tach a single threaded client benchmarking tool ?, can you run multiple instances or hit the MD3000i from mulitple servers and measure the performance ?

    Server class storage devices are designed to perform best when serving requests from simultaneous multiple connections. If HD Tach is single threaded and your running it from one system, it might not be generating enough workload. Have you tried IOmeter ?
  • Forgot about the active/active part of your question. It simply means that both RAID controllers are serving out the virtual disks. When you create a virtual disk it will assign it to a RAID controller in slot 0 or slot 1. When you create the next one it will assign it the the other one, and so on.

    Under the "modify" tab you can change the virtual disk ownership and "balance" the virtual disks across the controllers if you find that some virtual disks are used more heavily and one controller is handling most of the workload.

    So if you created 2 virtual disks, you should be active/active. If you only have one virtual disk you are active/passive.