SQL Server Performance

Slow Disk I/O

Discussion in 'SQL Server 2005 Performance Tuning for Hardware' started by DavidDay22, Jul 27, 2007.

  1. DavidDay22 New Member

    I have a Dell 2850 with 8 gigabytes of ram and duel 2.80 Ghz, running under Server 64 bit Enterprize, with SQL 2005 64 bit.

    My disk I/O seems slow, I have 6 15K 146 gigabytes disks in raid 10 connected to a PERC 4e/Di as C drive, and the data and logs split between to arrays of 6 15K 146 gigabyte disks in raid 10 connect to a PERC 4/DC.

    Here are my numbers:
    In memory read test
    spidCallsmsCPUmsCallsPerSecRowsPerCallRowsPerSec
    60254145300009328471.5 10 84715
    6093704300009353123.46730 93704.01
    6035069300009371168.967100 116896.7
    60352730000938117.56671000 117566.7

    Random I/O
    spidCallsmsCPUmsCallsPerSecRowsPerCallRowsPerSecReadsPerSecRead MB/secAvg-sec/IO
    613093001678110.294510102.9451200.32651.56514.9687
    61194300169036.463220129.2644202.35871.58094.9254
    616463001390421.524030645.7202751.67435.872511.9531
    615533000086518.433350921.6667946.63347.395611.9289
    61338300763111.23821001123.82001121.99108.765611.8584
    6112830016244.26443001279.31801263.26009.869212.1472
    614130406231.348410001348.41801286.851010.078712.1770
    611931326360.606530001819.54301750.750013.71149.7875
    61735250480.198699981985.50401880.340014.72659.3380

    spidCallsmsCPUmsdpages/sMBTable MB/secReadsPerSecDisk MB/secAvg-sec/IO
    57128428678714753.8232768115.2642234.7178115.46498.2660
    57126022086816118.3032768125.9242256.1909126.143415.1261

  2. satya Moderator

    If you have tempdb on those drives which are observing slow I/O, thenrefer to this blog and see this too to check whether you have enabled the online indexing in thsi case.
  3. DavidDay22 New Member

    The read performance for an array of 6 15K drives connect directly connected to a PERC 4/DC controller seems very low, it is almost like somewhere it is throttled
  4. satya Moderator

    Have you collected the SYSMON counters for further assessment, why not get checkout the hardware with the vendor.

Share This Page