Raid/Alocation unit on new server

ovicash
ovicash Member Posts: 141
edited 2007-06-11 in SQL General
Helo guys

I have two issues:

1)

I have a new server for the Navision Database. It will have Sql 2005 x64, Windows 2003 Server 64.

I have 3 RAID 10 systems for the database. I intend to use one for transaction log and I am wandering what to do with the two left:
- split the database in 2 (using the same filegroup by creating 2 data files within navision) OR
- put the tabledata on the first array and move the indexes/sifts on the second one. Has anybody used a script for doing that for all tables in database?

2) As I read on the Internet it is best to use FAT32 for the database systems, especialy for the transaction log (true?). Another thing related to this is the allocation unit size on the disks. One Extent has 8 pages, one page has 8k. As far as I know SQl reads optimum 1 extent at a time...so alocation unit size should be 64 k for maximum perfomance? Am I right?

Any opinion is very apreciated

Thank you

ps: some interesting mibuso topics related

http://www.mibuso.com/forum/viewtopic.php?t=12469
http://www.mibuso.com/forum/viewtopic.php?t=11468
http://www.mibuso.com/forum/viewtopic.php?t=10335
http://www.mibuso.com/forum/viewtopic.php?t=16342
ovidiu

Best Regards

Comments

  • bbrown
    bbrown Member Posts: 3,268
    How large are the RAID 10 arrays? How many physical drives and what size.

    Use RAID 1 for the transaction log. If you expect it to exceed the size of one drive then use multiple RAID 1 sets.

    Use NTFS for all drives.
    There are no bugs - only undocumented features.
  • ovicash
    ovicash Member Posts: 141
    bbrown wrote:
    How large are the RAID 10 arrays? How many physical drives and what size.

    Use RAID 1 for the transaction log. If you expect it to exceed the size of one drive then use multiple RAID 1 sets.

    Use NTFS for all drives.

    The Raid system is using 4X73Gb disks
    ovidiu

    Best Regards
  • bbrown
    bbrown Member Posts: 3,268
    Am I correct that you have 3 RAID 10 arrays (each 4x72GB). Totaling 12 physical drives?

    Are they all on the same controller/subsystem? if yes, then break them apart and reconfigure as a RAID 1 + RAID 10. This assumes these are for the DB and other drives are available for O/S etc.


    How large is the database?
    There are no bugs - only undocumented features.
  • ovicash
    ovicash Member Posts: 141
    bbrown wrote:
    Am I correct that you have 3 RAID 10 arrays (each 4x72GB). Totaling 12 physical drives?

    Are they all on the same controller/subsystem? if yes, then break them apart and reconfigure as a RAID 1 + RAID 10. This assumes these are for the DB and other drives are available for O/S etc.


    How large is the database?

    The OS is on separate disks. The 12 disks are for the database only.

    So you say Raid 1 is best for TL? Momentary the tempbd is on OS disks. Should I split the RAID 10 intended for the TL in two RAID 1 : for the TL and Tempbd?
    ovidiu

    Best Regards
  • bbrown
    bbrown Member Posts: 3,268
    How about the following config:

    Drive 1: RAID 1 (2x72 gB) - Navision TRansaction Log

    Drive 2: RAID 1 (2x72 GB) - Default SQL databases (master , msdb, tempdb) + Navision primary data file

    Drive 3: RAID 10 (8x72 GB) - Navision secondary data file
    There are no bugs - only undocumented features.
  • ovicash
    ovicash Member Posts: 141
    okey thx Bbrown,

    Related to the other issue regarding alocation unit, does anyone have some clear thoughts?
    ovidiu

    Best Regards
  • Nobody
    Nobody Member Posts: 93
    Disk alignment can have a significant impact on disk performance so make sure the offset is set correctly for each partition. The allocation or stripe size should be >=8k to prevent torn pages, a 64k block size makes the most sense as it matches the size of the SQL Server Extent (8 – 8K pages).

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