RAID protects you from catastrophic data loss due to drive failure.
Of course, you need to actually back it all up to yet something else.
I have a 4 disk enclosure (qnap 409) w 3 drives: 2 of them for a RAID 1 and the other as independent backup of the RAID 1. That puts my data on 3 separate drives. Purists will say the backup should be external etc etc and I agree but that's my current system that I'm reasonably happy with.
umeboshi wrote:
sjms: are you using the second generation Drobo or first? If you are using the second gen. what are your impressions? It is impossible to find reviews at this point and I would like to hear from someone who has one before I actually purchase one.
brand new out of the box gen 2. it is not the speediest thing on the planet but its doing a whole bunch of management things inside while it sits there humming. i work on batch items rarely and individual images all the time so management is easy and its fast enough for my use. currently now have 400GB of images on it
Drive security, like any security, is all about layers of protection and how many layers is right for any given person is an individual choice. 2 drives in RAID 1 in a machine is fine, even if it is software based. Having nearline storage and offline storage, the latter in particular, is critical.
A couple of years ago a bolt of lightning hit a tree a hundred metres from my house. My house alarm, tv, cable, quite a bit of stuff, got fried. Luckily, this happened while I was asleep but I woke up very quickly when the house alarm went off. Again, luckily, my workstation and nearline drive were all unplugged from the mains at the time. My neighbour was not so lucky, his PC was still powered up but in sleep mode and he lost nearly all his data apart from a few old DVD backups. Yes, his PC was protected by a very good surge protector as well, not that it made much difference.
Consider very carefully what you do. RAID provides only very limited protection against lost or corrupted files. Experience with software RAID is not assuring, it's a low cost solution and has failure modes that cannot be overcome-- low likelihood, but devastating when it happens. The same can be said about the hardware solutions. Many have proprietary controllers and data corruption may not be recoverable, except at very high cost. The bottom line is you can't trust any RAID for archival storage. You must have a backup strategy. AND you don't know if you have a real backup strategy until you try to do a restore. Caveat emptor.
I had raid 1 and Dell talked me out of using it. As is mentioned above, there are a number of failure types that cannot be recovered with raid 1.
I split the drives (2 x 500 GB). One is on-line for active backup. The second is off-line in a fireproof safe. About once a month I swap the two drives. Since I have two copies of everything and a a third copy that is at most a month out of date, I feel relatively safe.
Having said that, I am now trying an experiment, backing up on-line to Mozy. For home use it is $5/month with no quota. However it will take 3-4 weeks to copy my 320GB of data using a "high speed" cable connection. Once the initial backup is done, keeping it current should not be a problem.
