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Am 28.04.2010 03:41, schrieb Iain Buchanan: |
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> Hi, |
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> |
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> A winblows colleague said he uses a utility to backup his internal hard |
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> drive to an external disk, such that if his internal disk fails he can |
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> replace it with the external disk and continue straight away. |
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> |
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> Since I go to weird locations with unreliable power and sometimes drop |
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> my laptop I thought it should be simple to do the same in Linux. I have |
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> an external disk the same size, but now what? |
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> |
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> * I want to copy changes intelligently (ie. no dd, gparted, or |
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> Ghost4Linux). |
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> * I want to copy a specific device only (no usb keys, etc) to a |
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> specific external device. |
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> * Windows partitions can be ignored. |
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> * It doesn't matter if the copy is not unmounted properly, eg. if |
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> power is shut of without shutting down. |
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> * The external disk must be able to be absent |
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> |
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> Can md use one internal and one external disk in a RAID 1 setup, with |
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> the external disk not always there? Any other suggestions? |
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> |
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> thanks :) |
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md would be extremely slow because it has to rebuild/resync the complete |
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array. |
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|
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I suggest you manually recreate the partitioning scheme, install grub, |
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then mount it with some little script and call some backup tool to do |
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the actual copying. |
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|
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If you can live with just one big partition as a backup (probably with |
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separate /boot), you should replace fstab and grub.conf on the backup |
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medium and blacklist them from the files which you want to back up. |
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Concerning the backup tool, I would use `rsync --delete` plus all |
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relevant switches for permissions, times, acls, etc. If you use another |
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tool, just make sure it doesn't put some metadata onto the backup medium |
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and that it can delete files which no longer exist on the original medium. |
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|
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With regard to your requirement to just 'pull the cord' without |
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umounting it: Better mount it with '-o sync' to increase your chance |
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that everything works fine afterwards. But in reality, nothing can |
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really protect you from filesystem corruption in this situation. If you |
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can afford, better keep two backup media which you round-robin. |
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|
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Hope this helps, |
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Florian Philipp |
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