fakeraid1 better performance than raid10, why?

Discussion in 'Technical' started by tremolo, Feb 18, 2009.

  1. tremolo

    tremolo New Member

    Hi, Installed a new NAS today and got some pretty bad results. Slower performance with 8x500G disks in raid10 compared to 2x250G disks in (fake)raid1.

    # Machine 1, Dell poweredge 840 dual core, 2.2ghz xeon.
    Debian Lenny, Raid 10, 8x500G barracuda SATA2 (16mb) EXT3: LSI card 256M. 02:0e.0 RAID bus controller: Dell PowerEdge Expandable RAID controller 5.
    stripe element size = 64Kb
    read policy: Adaptive read ahead
    write policy: write back

    Timing cached reads: 2406 MB in 2.00 seconds = 1202.57 MB/sec
    Timing buffered disk reads: 170 MB in 3.07 seconds = 55.38 MB/sec

    1G file of /dev/zero: 1073741824 bytes (1.1 GB) copied, 7.11499 s, 151 MB/s

    # Machine 2, Dell R200, quad core xeon 2 ghz
    Debian etch, (fake) raid 1, 2x250G SATA2 (16mb) EXT3: 02:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1068E PCI-Express Fusion-MPT SAS (rev 08)
    Timing cached reads: 7038 MB in 2.00 seconds = 3523.09 MB/sec
    Timing buffered disk reads: 62 MB in 1.10 seconds = 56.32 MB/sec

    1G file of /dev/zero: 1073741824 bytes (1.1 GB) copied, 5.99594 seconds, 179 MB/s

    What might the problem be?

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