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On 28/04/2015 17:24, Neil Bothwick wrote: |
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> On Tue, 28 Apr 2015 17:01:49 +0200, Alan McKinnon wrote: |
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> |
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>> When you use only LVM for this and nothing else, you have a high risk of |
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>> losing everything if one disk fails. Why? Because LVM decides itself |
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>> which extent it will put data on. Maybe a whole file is on one disk, |
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>> maybe it's spread across two, because the software is designed so that |
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>> you don't have to be concerned with that. The only thing that LVM does |
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>> is expand your storage space as a single volume and make it easier to |
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>> shuffle things around without having to backup/repartition/restore. |
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> |
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> An alternative is to create a new volume group on the new disk and mounts |
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> PVs at various points in your home directory. That way you get the extra |
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> space and much of the flexibility without the risk of a failure on a |
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> single drive taking out data on both. However, if you are concerned about |
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> data loss, you should be using RAID t a minimum, preferably with an error |
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> detecting filesystem. |
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I've used that scheme myself in the past. You do get the increased space |
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but you don't get much in the way of flexibility. And it get COMPLICATED |
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really quickly. |
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To get around the situation of one drive almost full and the other |
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having lots of space, folks often use symlinked directories, which you |
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forget about and no-one else can figure out what you did... |
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It all smacks of the old saw: |
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For any non-trivial problem, there is always at least one solution that |
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is simple, elegant, and wrong. |
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |
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