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On 28/04/2015 10:39, Dale wrote: |
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> Howdy, |
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> |
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> I have a 3TB hard drive that I use for my /home partition. I'm going to |
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> be having to expand this before to long, lots of videos on there. The |
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> 4TB is a bit pricey and I would end up having to expand that to before |
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> to long. So, I got to thinking, why not buy another 3TB drive and just |
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> add that which would double my space. I use LVM by the way. I may try |
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> BTFS, (sp?). Either way, adding a drive shouldn't be to much of a |
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> problem. |
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> |
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> On one hand, adding a drive would double my space. It would also spread |
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> out my stuff in the event a drive failed. On the other hand, one more |
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> drive to have spinning that could fail too. These large drives makes me |
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> wonder sometimes. |
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> |
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> What do you guys, gals too, think about this? Just add a drive or buy a |
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> larger drive and move things over? Or is this a six of one and half |
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> dozen of the other thing? |
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> |
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> Dale |
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> |
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> |
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> |
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> P. S. |
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> |
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> |
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> Filesystem Size Used Avail Use% Mounted on |
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> /dev/mapper/Home2-Home2 2.7T 1.8T 945G 66% /home |
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> |
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> |
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> |
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When you're up into the TB range you run a higher risk of losing data |
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than with disks of a few 100 GB simply because it's bigger and there are |
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more bits that can flip [1]. |
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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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The best solution for you depends on what you need and what you have. If |
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your disks are full of YouTube videos that you can easily download again |
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(or stream), maybe you don't care too much. Precious family photos that |
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can't be replaced? You need to care a lot. |
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Personally, I like the ZFS approach and do it all in software, catching |
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errors that RAID misses. |
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RAID is also an option - 1:1 mirroring works great if you are much more |
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concerned about data than about cost. |
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There is no general advice in this area[2], the trick is to understand |
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the various technologies, fully understand your own needs and budget, |
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then plan accordingly. |
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[1] All things being equal that is. A 3TB disk is probably not really |
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the same as a 500G disk, just bigger. It's safe to assume that disk |
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manufacturers pat attention to error rates etc and improve their |
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products over time to make them more reliable. As to by how much - I |
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don't know. |
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[2] There is however a vendor's desire to maximize their profit while |
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still leaving you with warm and fuzzies </sarcasm> |
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |
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