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RAID 1 TO RAID 5 CONVERSION

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RAID 1 TO RAID 5 CONVERSION

cmdx2
I am trying to convert RAID 1 to RAID 5 without losing my data. Is there a way to convert/reconfigurate my RAID without formating, reinstalling and configurating all the software? Thanks in advance!
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    cmiller5400

    What mfr of RAID are you using. Is in onboard, or a card? Is it software based raid?

    Most likely it is going to be a wipe the array, and rebuild. You may be able to ghost the machine to just restore the data/os partitions, but good practice is backup, backup, then backup again for good measure.

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    ugadata

    The only way not to lose your data is to back it up first.

    Now, when you say "data" do you mean installed programs, the installed OS, and data created/stored by existing programs? If so you'll need some kind of image backup software (as compared to a file backup software) at least for partition containing the OS.

    Is the RAID being implemented in software or is it hardware (I hope it is implemented in hardware, makes life much simpler).

    I doubt there is any way to do an in-place conversion from RAID 1 to RAID 5.

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    cmdx2

    Guys,

    This is where I am at: I basically want to keep the data on the server and do the conversion with HP ACU.
    I am aware I can break the mirror (backup, backup, backup) and configure from HW however at this point
    I would prefer to use the ACU. I value any suggestions provided, Thanks.

    Here is some info :
    HP ProLiant DL G4
    hw - Smart Array 6i Controller - onboard
    sw - ACU

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    0 Votes

    X

    CCallalou

    X

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    0 Votes
    DomBenson

    Yes - the HP ACU (array configuration utility) and hpacucli support doing this. It is called Online RAID Level Migration, and it is referred to in the ACU user guide:
    http://h10032.www1.hp.com/ctg/Manual/c00709035.pdf
    You should be sure to have a backup first, and it is strongly recommended to have the BBU/FBWC upgrade - some of the Smart Array controllers simply won't do ORLM if this isn't present.

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    chris2mop

    You said " I want to add two more disk same capacity and same model."
    I can suggest you to add same capacity disks,but NOT same model: in case of disk defect, you can crash several disks in a relative short time (may be several disks at the same time). I have experimented this problem in a raid 5 array and thanks to backup i could recover my data. the array was dead (2disks).
    Chris

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    0 Votes
    DomBenson

    The risk with using different models is that, rather than reducing the impact of defects, you increase the chance that you will be affected by them, as you are exposed to two sources.
    It can also make performance worse, as the RAID controller has to accommodate the lowest common denominator for each operation.
    To reduce the risk of multiple failures occurring in a short window, periodically migrating between hot spares can help, as is causes all the disks to have different wear profiles. Staying on top of SMART data (for SATA drives) is also a must!

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    0 Votes
    info

    I'm inclined to agree with UGAData on this. The one piece of data we're missing to be sure is how many drives we're talking about in the RAID1 source and RAID5 target arrays. For instance:
    Your source array is RAID1 with two drives. If you add an additional drive to the system this may be possible, as it could keep it's original data on the single drive while populating the other disks with data, once finished, it could stripe the data with the parity information and complete the RAID5 migration.

    I have a number of those G4s (bought for $100 each! ), mostly as parts spares for one I still have in operation at a very small branch office. Don't know if a Battery pack is required for RAID5 on servers that old like it is on newer ones. Ideally, the focus should be taking that server out of production and replacing it with a newer one, if you have the funding.

  • +
    0 Votes
    cmiller5400

    What mfr of RAID are you using. Is in onboard, or a card? Is it software based raid?

    Most likely it is going to be a wipe the array, and rebuild. You may be able to ghost the machine to just restore the data/os partitions, but good practice is backup, backup, then backup again for good measure.

    +
    0 Votes
    ugadata

    The only way not to lose your data is to back it up first.

    Now, when you say "data" do you mean installed programs, the installed OS, and data created/stored by existing programs? If so you'll need some kind of image backup software (as compared to a file backup software) at least for partition containing the OS.

    Is the RAID being implemented in software or is it hardware (I hope it is implemented in hardware, makes life much simpler).

    I doubt there is any way to do an in-place conversion from RAID 1 to RAID 5.

    +
    0 Votes
    cmdx2

    Guys,

    This is where I am at: I basically want to keep the data on the server and do the conversion with HP ACU.
    I am aware I can break the mirror (backup, backup, backup) and configure from HW however at this point
    I would prefer to use the ACU. I value any suggestions provided, Thanks.

    Here is some info :
    HP ProLiant DL G4
    hw - Smart Array 6i Controller - onboard
    sw - ACU

    +
    0 Votes

    X

    CCallalou

    X

    +
    0 Votes
    DomBenson

    Yes - the HP ACU (array configuration utility) and hpacucli support doing this. It is called Online RAID Level Migration, and it is referred to in the ACU user guide:
    http://h10032.www1.hp.com/ctg/Manual/c00709035.pdf
    You should be sure to have a backup first, and it is strongly recommended to have the BBU/FBWC upgrade - some of the Smart Array controllers simply won't do ORLM if this isn't present.

    +
    0 Votes
    chris2mop

    You said " I want to add two more disk same capacity and same model."
    I can suggest you to add same capacity disks,but NOT same model: in case of disk defect, you can crash several disks in a relative short time (may be several disks at the same time). I have experimented this problem in a raid 5 array and thanks to backup i could recover my data. the array was dead (2disks).
    Chris

    +
    0 Votes
    DomBenson

    The risk with using different models is that, rather than reducing the impact of defects, you increase the chance that you will be affected by them, as you are exposed to two sources.
    It can also make performance worse, as the RAID controller has to accommodate the lowest common denominator for each operation.
    To reduce the risk of multiple failures occurring in a short window, periodically migrating between hot spares can help, as is causes all the disks to have different wear profiles. Staying on top of SMART data (for SATA drives) is also a must!

    +
    0 Votes
    info

    I'm inclined to agree with UGAData on this. The one piece of data we're missing to be sure is how many drives we're talking about in the RAID1 source and RAID5 target arrays. For instance:
    Your source array is RAID1 with two drives. If you add an additional drive to the system this may be possible, as it could keep it's original data on the single drive while populating the other disks with data, once finished, it could stripe the data with the parity information and complete the RAID5 migration.

    I have a number of those G4s (bought for $100 each! ), mostly as parts spares for one I still have in operation at a very small branch office. Don't know if a Battery pack is required for RAID5 on servers that old like it is on newer ones. Ideally, the focus should be taking that server out of production and replacing it with a newer one, if you have the funding.