How does this computer backup drive work?

jwbryson1 · May 31, 2013

I have this backup drive from G Technology, but mine just has 2 of the 1T drives instead of 4 as shown here: G-Technology 4TB G-SPEED Q External Hard Drive Array 0G01792 B&H.

If I wanted to buy another backup drive and swap out one of these, when I insert the new drive does it automatically copy what is located on the second drive, or do I have to prompt it to copy?

In other words, if I pull out the top drive and replace it with a new, empty drive, will the new empty drive copy everything off the second (bottom) drive?

How does this work?

Thanks!

Gavjenks · May 31, 2013

RAID arrays use various schemes to give you data redundancy OR speed increases OR both.

The system you linked to supports two modes: RAID 0 or RAID 5.

In RAID 0, there will be no redundancy of data (no extra safety net), but your reading and writing speeds will increase dramatically (it stores files across multiple drives so that you have multiple drives working at full speed during loading instead of one, cutting the time to a fraction of what it would be for one drive). This is fairly useless for photography, probably, because not much time is spent loading images into programs or saving them. Editing is what uses up the most time (in my experience anyway).

In RAID 5, part of each drive is used for redundancy data (to make it more likely you can lose a drive and still not lose data), and part is used for moderate speed increase. It's sort of a compromise between the two extremes possible. You could probably lose ONE of your drives in the array and not lose data, but not more than 1. And it won't be as fast as RAID 0. Still faster than a normal computer hard drive though.

Neither mode allows you to just yank out drives willy nilly. Your data is distributed across them, and they work as a team. If you yank out a drive in RAID 0, you will lose all your data, I think. If you yank out a drive in RAID 5, it can compensate, but it will put stress on the other drives, and you can't yank out 2.

If you want just basic backup and don't care much about extra read/write speed, then a RAID is way more expensive than what you need. Just go buy a $50 external hard drive or two and copy all your stuff to it. Maybe use a sync program to make it easier. Done-zo. Not $800 RAID setups.

And in some cases, external hard drives would be better anyway, because they are disconnected when in storage, so you don't have to worry about them getting hit by heavy electrical surges (which could take out your computer AND your entire RAID array at once...)

If you want double backups, get an external hard drive + make CD/DVD copies of your work occasionally

Another cheap possibility for somebody who wants long term storage that they don't intend to use very often or ever is Amazon Glacier: http://aws.amazon.com/glacier/pricing/ 1 penny per GB a month, but is very expensive to access all at once (cheap to access slowly and in small amounts. up to 0.2% of total storge can be retrieved daily for free.). For say... 10GB of storage, you would pay $1 a month, and if you lost everything, you could retrieve up to a few images per day for no cost. If you would want faster recovery than that, there are other more expensive but less penalized for fast recovery plans too.

jwbryson1 · May 31, 2013

Gavjenks said:
Neither mode allows you to just yank out drives willy nilly.

The specs say that the hard drives are hot swappable so if there is a HD failure, you pull the bad HD and put in a new one. In RAID 5, I think it automatically rebuilds the lost data in the new drive. I'm not sure about RAID 0.

Buckster · May 31, 2013

"Hot Swappable" is pretty unambiguous, but your specific questions are probably best answered by the manufacturer. Here's their web site: G-SPEED Q - RAID 0,5 Storage Up to 16TB | G-Technology

I use similar external multiple hard drive bay enclosures for an additional 10TB of redundant backup storage using an eSATA interface, and it works great for me. Here's a post about it that I made quite a while ago (2009): http://www.thephotoforum.com/forum/...ng-file-storage-alternatives.html#post1726258 (I've since changed out the smaller drives and added a few more drives, so I'm now at 15TB total)

I bought the enclosures, drives, port multipliers and cables separately, and saved money doing it that way by shopping around for them. I also chose not to go with a RAID configuration after being burnt by one years before putting that together - the data was not retrievable on two drives after a catastrophic failure, and if not for even more backups I had of it all, it would have been lost to me. ESATA is plenty fast enough for my needs, and I'd rather just add drives (as cheap as they are these days) than take a chance by splitting up my data in a RAID scheme, but that's just me - I like things to be straightforward.

I use Allway Sync Pro to keep my on-site backups up to date, and also upload to a couple of servers online to maintain off-site backup, the latest being CrashPlan, which I'm finding to be a really good value for the low price they charge.