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Question on SAN

  • October 24, 2003 at 3:03 am

    #81322

    Hi there,

    it happens that our IT staff is asking me on hardware consideration for our datawarehouse.

    Now, what I know is everything is on a SAN (Assume, that I don't know exactly what this is).

    Question 1: Is it possible to restore a db, even if the size of that db is larger than the free space on a single drive in the SAN?

    Question 2: If answer to 1 is no, the database needs to be splitted. Is this a case for partitioned views?

    Frank

    http://www.insidesql.de

    --
    Frank Kalis
    Microsoft SQL Server MVP
    Webmaster: http://www.insidesql.org/blogs
    My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

  • October 24, 2003 at 6:02 am

    #479435

    A SAN(Storage Area Network) Is a collection of disk that can be accessed by multiple host. They usually split these disk up into groups to make RAID 5 or 1 or 10 arrays that are then exposed to the host as a logical drive letter, that is a simple view of them.

    1. SAN's don't change the laws of physics. If the DB is too large for the drive its too large for the drive.

    2. You can have multiple files on multiple drives and not have to partition the database out manually. This may be a case for a partitioned view but I highly doubt it. Look at adding files to the PRIMARY file group or adding addtitonal filegroups to spread your database across the SAN.

    Tell your hardware team how much space you will need on the SAN. It will be broke up into data space and log space. Data space should have it's own drive letter as should log space. If they can't give you all the data space as one drive letter break it up evenly across drive letters. Tell them you want the log space to be RAID 1 or RAID 10 and you also want the dataspace to be RAID 1 or 10 for performance reasons. Beat them with a stick if they tell you RAID 5. in a dataware house you have a ton of loads that have to happen RAID 5 can really slow you down.

    This is a huge generalization, if you don't have the knowledge to build this out I would highly recommend bringing a dataware housing consultant in.

    Wes

  • October 24, 2003 at 6:11 am

    #479438

    Thanks for reply!

    I'm not going to decide on this topic.

    They just asked me what I think and I said I don't know. But I'm pretty sure they'll get in another consultant.

    However in the meantime I was advised to take a look at 'Split mirror backup technology'.

    Any experiences/comments on this ?

    Frank

    http://www.insidesql.de

    Edited by - Frank Kalis on 10/24/2003 06:12:38 AM

    --
    Frank Kalis
    Microsoft SQL Server MVP
    Webmaster: http://www.insidesql.org/blogs
    My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

  • October 24, 2003 at 6:16 am

    #479441

    Generally, if your datawear house doesn't have to be available 24 hours a day and can sustain the down time a mirrored backup isn't needed. You generally have to have as much freespace on the SAN as the size of the database you are going to mirror for backup purposes. Business copy is kind of the same thing it allows you to "split" a mirror of the drives and then attach to them via another server to have a read only copy or a copy that you can then put onto tape. I would look at SQL LiteSpeed from DBAsocciates and back it up to an empty drive on the san or off the san. Size of the wearhouse will also help you make a choice on how to back it up.

    Cheers,

    Wes

  • October 24, 2003 at 6:19 am

    #479443

    Hi Wes,

    great, that's all I need. I don't want to dive too deep into this and leave them with your answer.

    Thanks again!

    Frank

    http://www.insidesql.de

    Sorry, typo

    Edited by - Frank Kalis on 10/24/2003 06:22:29 AM

    --
    Frank Kalis
    Microsoft SQL Server MVP
    Webmaster: http://www.insidesql.org/blogs
    My blog: http://www.insidesql.org/blogs/frankkalis/[/url]

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