On 28/04/2015 10:39, Dale wrote: > Howdy, > > I have a 3TB hard drive that I use for my /home partition. I'm going to > be having to expand this before to long, lots of videos on there. The > 4TB is a bit pricey and I would end up having to expand that to before > to long. So, I got to thinking, why not buy another 3TB drive and just > add that which would double my space. I use LVM by the way. I may try > BTFS, (sp?). Either way, adding a drive shouldn't be to much of a > problem. > > On one hand, adding a drive would double my space. It would also spread > out my stuff in the event a drive failed. On the other hand, one more > drive to have spinning that could fail too. These large drives makes me > wonder sometimes. > > What do you guys, gals too, think about this? Just add a drive or buy a > larger drive and move things over? Or is this a six of one and half > dozen of the other thing? > > Dale > > > > P. S. > > > Filesystem Size Used Avail Use% Mounted on > /dev/mapper/Home2-Home2 2.7T 1.8T 945G 66% /home > > >
When you're up into the TB range you run a higher risk of losing data than with disks of a few 100 GB simply because it's bigger and there are more bits that can flip [1]. When you use only LVM for this and nothing else, you have a high risk of losing everything if one disk fails. Why? Because LVM decides itself which extent it will put data on. Maybe a whole file is on one disk, maybe it's spread across two, because the software is designed so that you don't have to be concerned with that. The only thing that LVM does is expand your storage space as a single volume and make it easier to shuffle things around without having to backup/repartition/restore. The best solution for you depends on what you need and what you have. If your disks are full of YouTube videos that you can easily download again (or stream), maybe you don't care too much. Precious family photos that can't be replaced? You need to care a lot. Personally, I like the ZFS approach and do it all in software, catching errors that RAID misses. RAID is also an option - 1:1 mirroring works great if you are much more concerned about data than about cost. There is no general advice in this area[2], the trick is to understand the various technologies, fully understand your own needs and budget, then plan accordingly. [1] All things being equal that is. A 3TB disk is probably not really the same as a 500G disk, just bigger. It's safe to assume that disk manufacturers pat attention to error rates etc and improve their products over time to make them more reliable. As to by how much - I don't know. [2] There is however a vendor's desire to maximize their profit while still leaving you with warm and fuzzies </sarcasm> -- Alan McKinnon alan.mckin...@gmail.com
