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Image Backup / Restoration issue

Discussion in 'Backup / Archive Discussion' started by ganpath, Sep 20, 2011.

  1. ganpath

    ganpath New Member

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    Hi

    I am new to TSM 6.2 . Server and Client is running on AIX 6.1. I have around 100 RAW Devices (Not Volumes) used by Oracle application. While taking image backup of these RAW Devices , Backup is completed with the following warning

    Image backup of volume '/dev/gl_system_02'
    Unable to take a JFS2 snapshot for volume '/dev/gl_system_02'.
    Operationwill be performed without using a snapshot.
    Using static image backup for volume '/dev/gl_system_02'

    The restoration Process result in Corrupted Block data hence Unable to mount my Oracle Database.

    Can somebody help me to rectify this issue
     
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  3. sjl

    sjl Member

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    Okay.

    When TSM is told to take an image backup, it assumes that it's backing up a filesystem. AIX provides native tools to perform snapshots of JFS and JFS2 filesystems. So it's designed to exploit those tools, take the snapshot, and thereby create a static image of a potentially dynamic volume.

    Since Oracle is using a raw device, there is no filesystem, and hence, no native snapshot tools. TSM will still backup the raw device, but this is a warning to indicate that it can't take a snapshot, so if Oracle writes to the device while the backup is taking place, the potential is there for the restore to be inconsistent (unless you have logging running so Oracle can replay the offending transactions upon restore.)

    Two questions spring to mind:
    1. Why are you using raw devices? What's wrong with just using a bog standard filesystem, and creating large files for Oracle to put its data inside? These days, the performance benefits are nowhere near as significant as they used to be, and I'd argue that it could cause more confusion than it's worth.
    2. Why are you not using TDP for Oracle? If it's important enough to put into an Oracle database, surely it's worth the money to pay for a bog standard hot backup tool that pretty much any TSM admin worth his (or her) salt knows well?
     
    Mita201 likes this.

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