Databas I/O shared RAID 10 vs single disks

  • Hello,

    I'm currently hosting a game server with the current specification

    E1230

    32GB Ram

    2x 1Tb SATA

    Windows 2008 server

    SQL Server 2012

    Databse size is 10Gb

    Number of players 1k

    - The problem at first I had I/O bottleneck with 2x1Tb as I was using the default SQL configuration and all the files .mdf and .ldf were stored in default C:/SQLSERVER

    - Then I added 2 more 1 Tb disks and I isolated .mdf and .ldf and TempDB locations. Problem has been fixed and I/O is performing well.

    - Now I have the opportunity to change the disks system to 4x 300GB SAS in HW RAID 10, the problem I'm limited to 4 Disks 1 Array only, so I will have to store mdf, ldf and tempdb files in the same array and not isolated.

    - Will I have I/O issue with this configuration? it will be better than 4x single HDD's which every physical HDD contains mdf, ldf, and tempdb files which I already use at the moment without issue or performance could be worse with shared 4x SAS 300GB RAID 10?

    Thank you

  • Will you absolutely have IO issues? No one can say based on the information provided. Are you more likely to have IO issues having data & log on the same drive (even on a great choice like RAID 10), yes, possibly. If you absolutely had to, especially since you're dealing with such a small database, maybe a seperate drive just for the log, non-raid. But I wouldn't do that unless I was for sure seeing IO issues. Even then, I'd suggest tuning the code first. That's usually a bigger problem than the hardware.

    "The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
    - Theodore Roosevelt

    Author of:
    SQL Server Execution Plans
    SQL Server Query Performance Tuning

  • I'd second Grant's note.

    You can do some calculations on throughput you're using now, based on counters. You might gain confidence on the IO throughput you need.

    However the other issue is with 4 separate disks that losing one disk means you lose data, or at least the server.

    Can you do 2 arrays, each a R1? That could provide some separation, but protection. You'd have to look at the IOPS there.

    Ultimately, better to tune the code as much as you can, which might give you more flexibility.

  • Thanks for replies,

    Unfortunately I don't know the throughput, I used a query to show how much read and write the db is doing and this is so far what I got,

    READS WRITES

    _40245492895956

    _62123111887901

    _24794411576825

    _9333641031770

    _505606822357

    _357625715876

    _437448592302

    _533440526738

    _482597321542

    _497186248593

    _298480185557

    _216236103251

    _877389101965

    _61373953058

    _4739247234

    _6032836772

    _5067133929

    _6367433888

    _12614813424

    _2032312473

    _1247212472

    _6069568602

    _62526226

    _554564100

    _1149732050

    _1865031932

    _74661851

    _299681427

    _1195861188

    _442321176

    _5520912

    _115526694

    _244758626

    _11942567

    _606264417

    _5702397

    _359351

    _5586342

    _49374285

    _115055238

    _3978214

    _242199

    _22881768

    _11775130

    _325320

    I was thinking is this configuration, as I'm limited to 4 HDD's only, I already ordered the SAS disks with RAID10 HW controller from the host provider but I can change the RAID configuration anytime.

    Looks RAID 10 4x300GB (1 partition 600GB) will not be ideal for storing OS, mdf, ldf and all the files or?

    So I was thinking to change the configuration to:

    C:/ OS (300GB SAS 1 Disk)

    D:/ MDF database files (RAID 1) (300GB SAS 2 Disks)

    E:/ LDF files and tempfb files (300GB SAS 1 Disk) ..... Will this configuration work better than the RAID 10 ARRAY?

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