SATA Drives and Raid 0

Discussion in 'Acronis True Image Product Line' started by Tatou, Feb 27, 2005.

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  1. Tatou

    Tatou Registered Member

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    I have been following the info on the need to backup a drive either by clone or by all partions rather than just the system partition on the drive to ensure that should the drive turn to custard (rather than just the data on the partition) that the system drive will reboot.

    So I have a two SATA drives 80 gig and 160 gig.(VIA Raid Controller) They are set up as RAID 0 with two partitions 80gig and 160gig.

    I also have an 80gig IDE attached to the Secondary IDE (DVD and CD are connected to the Primary IDE)

    I have been backing up the 80 partition to the IDE drive but not the 160gig as most of the data is large transitory videos files or photos already backed up to DVDs.

    Questions

    I assume if either of the SATA drives crashes enough to trash an MBR then because I have not been backing up the second partion it is unlikely that the restored system partition will boot?

    2 A crash of either drive will crash all partitions (this is the downside of RAID 0) ?

    Thanks
     
  2. pjb024

    pjb024 Registered Member

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    As long as you are backing up the partition that contains your operating system and from which you normally boot then you will be able to boot from a restore of that partition. You don't have to backup any partitions that contain data that you consider to be transitory but of course that means you will have an empty partition and all data will have been lost when you recreate your RAID 0 configuration.

    As a matter of fact you may not lose any data from your 80 gig partition in the event of a crash if it is the 'other' disk that crashes. Your 160 gig partition will be in RAID 0 config with a stripe set consisting of 80 gig on drive A + 80 gig on drive B. The remaining 80 gig is all on drive A or Drive B and not configured as RAID so it is only at risk if the drive it is on fails. The RAID partition however will be lost if either drive fails.

    Hope this helps.
     
  3. Acronis Support

    Acronis Support Acronis Support Staff

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    Hello Tatou,

    Thank you for choosing Acronis True Image (http://www.acronis.com/homecomputing/products/trueimage/).

    If you have the image of a single system partition and restore it to another drive it is not guaranteed that the system will boot then even if you fix MBR. However you will find several people here who managed to perform this operation and the system booted. Briefly, this may work but is not guaranteed. Anyway you may always mount the image you created and copy necessary files from it.

    Thank you.
    --
    Ilya Toytman
     
  4. Tatou

    Tatou Registered Member

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    Thanks Ilya

    So how do I make sure that a system partition will book OK when I have two drives configured as RAID 0?

    Thanks for reply
     
  5. feddup

    feddup Registered Member

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    Select the ENTIRE disk that contains the OS. Do this for create image as well as restore. This should contain the MBR.
     
  6. Tatou

    Tatou Registered Member

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    Thanks for info but if I have the two drives 80 and 160gig set as RAID 0 then isn't the C partition spread across the two drives?
     
  7. pjb024

    pjb024 Registered Member

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    If the two drives that you have in a RAID 0 configuration are not of the same size then the size of the RAID 0 array is equal to twice the size of the smaller disk. In other words you will have an array that uses all of your 80 gig drive and 80 gigs of your 160 gig drive. The remaining 80 gig from the larger drive is NOT part of the array and functions as a standard partition. RAID 0 should use same size disks for best performance and performance is the only reason for choosing RAID 0 as there is no data protection and you will lose your data in the event of a single drive in the array failing. Also bear in mind that if you are choosing RAID 0 for performance then it is a bad idea to have a non-RAID partition on the same drive as a partition that forms part of the array.
     
  8. Tatou

    Tatou Registered Member

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    Aha thanks for the explanation

    Does that mean it is likely I have 80 from the 80 gig and 80 from the 160gig as a RAID 0 array probably seen as my D drive which is 160gig and the remaining 80 from the 160gig is configured as C system drive and not part of the RAID array. I did choose RAID 0 for performance and got the shop who sold me the computer to set it up. How could I check if this is the case? I am running XP SP2 1gig RAM 3.2 P4.

    I suppose if I replace the 80 with 160 (to get two of the same size disks) I will have to remake the array and reinstall all my programmes. I have XP SP2 slipstreamed so it may not be too bad.

    THe other option I suppose if I have read it right is to:

    Clone the c partition with ATI
    Replace the 80 with another 160
    Redo RAID 0 array using the two 160gig drives
    restore c paritition
    If needed use repair on XP

    Maybe RAID 0 is not worth the trouble and I just should stick to two SATA drives?

    Thanks
     
  9. pjb024

    pjb024 Registered Member

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    Yes you have a Raid 0 array which is made up of 80 gig from the 80 gig drive and 80 gig from the 160 gig drive. There should be some kind of Raid utility that you have that will confirm this. I don't know whether you have a Raid card installed or does your motherboard have an onboard Raid controller? Anyways, yes you can get another 160 gig drive and that will let you build a 320 gig Raid 0 array. Whether you want to do that or go back to conventional SATA with no Raid depends on how much you want to have the performance benefit of Raid 0. Personally I would still want the Raid but that's me. It doesn't sound as if it would be too difficult for you to change your Raid config and you would only have to do it once so maybe it's something for you to think about but I wouldn't leave it as it is at the moment.
     
  10. Tatou

    Tatou Registered Member

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    Thanks pjb024

    You have given me a lot of good info. The RAID is on the motherboard. The only problem with a 360gig RAID 0 is backup with ATI on any partition is not guaranted to restore if a drive crash kills the mbr but I suppose I could fix the mbr with XP repair.
     
  11. pjb024

    pjb024 Registered Member

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    I know I have restored Raid 0 with ATI and not had any significant problems. You can either build a new array and restore to that or restore to a single drive and build the array as a second step.
     
  12. pjb024

    pjb024 Registered Member

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    I just realised your system drive is not Raid anyway and you said your 160 gig is only transitory data so it would seem a very simple task to set up a new array as it doesn't need anything restoring to it. You only need to restore the system partition to the 80 gig drive and fixmbr is not hard to do if you need to. Good luck anyway.
     
  13. Acronis Support

    Acronis Support Acronis Support Staff

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    Hello Tatou,

    It seems that I wasn't clear enough in my previous post. You cannot make sure the restored partition will boot normally until you try it. If you want a 100% guarantee please create the image of the whole drive (in your case RAID array). After you restore it it will certainly boot up.

    If it is data and not system that is of major importance to you then even if you won't be able to boot up the single restored partition you may install Windows and explore the image with the data then copying necessary files.

    Also please note that you may clone only disks, not single partitions. The workaround in this case is to create the image and to restore it then.

    If you have further questions please feel free to ask.

    Thank you.
    --
    Ilya Toytman
     
  14. ctal

    ctal Registered Member

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    If I am interpreting them correctly, comments in other threads indicate that performing a restore with TI overwrites the existing MBR whether or not it was previously corrupted. If so, you face the same issue whether or not "a drive crash kills the mbr." Perhaps someone else more knowledgeable could comment further.
    -- Al
     
  15. Acronis Support

    Acronis Support Acronis Support Staff

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    Hello ctal,

    Thank you for choosing Acronis True Image (http://www.acronis.com/homecomputing/products/trueimage/).

    Please note that MBR is rewritten only when you restore the image of the whole disk. If you restore a single partition Partition Table will be changed but not the whole MBR.

    Thank you.
    --
    Ilya Toytman
     
  16. Tatou

    Tatou Registered Member

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    THanks to Ilya and pjb024 for the info.
    Unfortunately I assume that the 80 gig system partition is not on the 80gig drive but the non RAID bit of the 160gig drive.[RAID 0 is 80 gig drive and 80 gig from 160gig drive]. Hence I can't clone it to get mbr.

    My conclusion is that I should have no trouble restoring the system partition from a normal image if its just corrupted data i.e trashed registry etc (excluding mbr) but a clone of the system partition is not possible due to it being a partition on the 160gig drive rather than a drive by itself.

    Thanks to all for help as I have learnt about RAID. I will look at two options.

    Making the 80gig IDE drive a system drive (which I can clone out to a USB drive) and replacing the 80gig SATA drive with a 160gig so I can set up a RAID 0 made up of 2x160gig drives. These will have transitory data on but will be fast and no backup needed with ATI.

    Leaving well alone (although having a non RAID partition on the 160gig is not the best)
     
  17. Anon

    Anon Guest

    Tatou here
    Well I learnt a lot from the answers but I was labouring under a misunderstanding from the beginning

    Just went back to computer shop to find that contrary to my belief I don't have a RAID 0 setup but two SATA drives (80 and 160) attached to an onboard RAID controller.

    So I can clone the 80 gig system and get the mbr. I am now happy

    Thanks to all who answered
     
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