Home > Ask the Storage Technology Experts > Questions & Answers > Migrating from DAS to a SAN
Ask The Storage Expert: Questions & Answers
EMAIL THIS

Migrating from DAS to a SAN

Christopher Poelker EXPERT RESPONSE FROM: Christopher Poelker

Pose a Question
Other Storage Categories
Meet all Storage Experts
Become an Expert for this site


Digg This!    StumbleUpon Toolbar StumbleUpon    Bookmark with Delicious Del.icio.us   


>
QUESTION POSED ON: 03 June 2005
I am looking at migrating from DAS to a SAN. The initial configuration will include three Windows 2003 enterprise clusters to store all data on the SAN. The second level will be to add Unix servers, Oracle databases and HP OpenVMS systems to the SAN. The SAN will start out with 4 terabytes (TB), two for production (FC drives) and two for mirror or snapshot. (SATA or FATA drives). Over the next two years, it will grow to 30 TB.

One configuration I looked at included:

  • Two FC drives -- RAID-5
  • Two SATA drives -- RAID-5
  • Full redundancy dual 16 port switches and dual single port HBAs in servers with load balancing software.
  • Basic managing software and snapshot software

    The second configuration was the same as above with 4 TB HP EVA5000 system combination FC drives and FATA drives managed by the OS.

    The OS managed system sounds good, but are the FC and FATA drives a two-tier solution or is it just 4 TB of storage, with no way to enhance performance or load balance?


  • >
    EXPERT RESPONSE
    Either configuration should work for your initial requirements. The first solution would provide discreet separate components, which would allow you to place the SATA array at distance from the production FC array. The second solution would provide two pools of storage within the same enclosure.

    Both provide a method of tiered storage, since the virtualization within the EVA can configure the different drive types as separate pools.

    As for flexibility and performance, you can configure different RAID types within the arrays to match the applications requirements. RAID-1 or RAID-10 is best for log file storage, and RAID-5 can house database-type storage. This would give you both two tiers of performance and two tiers of storage classes. Load balancing would be done at the host side using the path failover software. If you use volume management on the host side, you can stripe your LUN access across both HBAs for best performance.

    You mentioned 16 port switches. Since you also said your growth within the next two years would almost quintuple your requirements (from 4 to 30 TB, and addition of Unix and VMS servers), I would start out with more ports in the switches (Perhaps dual 32 port switches). If your budget does not allow for larger switches, then make sure the ones you buy will support zoning and trunking. As the SAN grows and you add more switches, you don't want to have to include multiple hops and many ISLs (inter-switch links). Moving to larger CORE type switches may be a better way to grow. Also note that Unix, VMS and Windows servers should be placed in separate zones within the fabric.


    Digg This!    StumbleUpon Toolbar StumbleUpon    Bookmark with Delicious Del.icio.us   


    RELATED CONTENT
    SAN management
    Storage Decisions New York 2008 Session Downloads
    Storage Decisions Session Downloads: Storage Systems & Networking Track (New York 2008)
    EMC, Pillar offer options to boost Oracle performance on storage disk arrays
    Quality Awards IV: It's a tie--EMC and NetApp share enterprise array honors
    Does SAP eat more than its share of storage?
    Solid-state drives quiz
    Windows Server 2008 steps on some storage toes
    Storage Decisions Chicago 2008 Session Downloads
    Storage Decisions Session Downloads: Storage Systems & Networking Track (Chicago 2008)
    Determining the number of drives in a RAID group
    SAN management Research

    Configuring RAID
    RAID-5 configuration
    RAID configuration with three hard drives
    Double drive failures in a RAID-10 configuration
    Server-based RAID vs. controller-based RAID
    RAID striping or concatenation
    Setting up RAID
    RAID groups and parity groups
    RAID: How safe is your data?
    Tech Report: Flexible RAID arrays
    RAID-10: Two great RAIDs that go great together

    RELATED GLOSSARY TERMS
    Terms from Whatis.com − the technology online dictionary
    Fast Guide to Storage Technologies  (WhatIs.com)
    fat provisioning  (SearchStorage.com)
    oversubscription  (SearchStorage.com)
    RAID  (SearchStorage.com)
    storage area management  (SearchStorage.com)
    storage area network  (SearchStorage.com)
    thin provisioning  (SearchStorage.com)
    unified storage  (SearchStorage.com)
    virtual provisioning  (SearchStorage.com)
    zoned-bit recording  (SearchStorage.com)

    RELATED RESOURCES
    2020software.com, trial software downloads for accounting software, ERP software, CRM software and business software systems
    Search Bitpipe.com for the latest white papers and business webcasts
    Whatis.com, the online computer dictionary



    Search and Browse the Expert Answer Center
    Search and browse more than 25,000 question and answer pairs from more than 250 TechTarget industry experts.
    Browse our Expert Advice



    Search for Data Management Tools and Tiered Storage Reseller Solutions
    TechTarget Storage Media
    Storage Magazine View this month\\'s issue and subscribe today.
    Storage Decisions Apply online for free conference admission.
    SearchStorage.com
    HomeNewsMagazineTopicsLearningMultimediaWhite PapersBlogsEventsAbout Us

    About Us  |  Contact Us  |  For Advertisers  |  For Business Partners  |  Site Index  |  RSS
    TechTarget provides enterprise IT professionals with the information they need to perform their jobs - from developing strategy, to making cost-effective IT purchase decisions and managing their organizations' IT projects - with its network of technology-specific Web sites, events and magazines.

    TechTarget Corporate Web Site  |  Media Kits  |  Reprints  |  Site Map




    All Rights Reserved, Copyright 2000 - 2008, TechTarget | Read our Privacy Policy
      TechTarget - The IT Media ROI Experts