RAID 5 as a backup?

[deveraux]

I am seriously considering setting up a RAID array to use RAID 5 as a backup solution. I don't have a server and currently, my backup involves using a separate hard drive that I attach only when I want to backup data. I don't really have any other feasible methods for backing up data as I have close to 120GB (increases quite often) and so backing all that up on dvd-r's is not exactly a good idea IMHO.

So, I was just wondering from people who have experience setting up RAID arrays, is using a RAID array a good method for backing up data? I have read that when using a RAID 5, multiple drives tend to fail around the same time (hence why RAID 6 was invented). I was just wondering about various people's experiences with RAID 5 and whether this really happens.

Thanks for your time!

 

[DaveSimmons]

search RAID for other threads on this. But to repeat myself:

Bad idea.

You can lose data from disk failure, other hardware failure (motherboard, PSU), virus / trojan / worm, other software problem, human error (deleting wrong file/folder), fire, flood, theft, powerline problem.


Right now your external drive protects you from all of those except probably a fire (since you probably keep it in the same location). RAID only protects you from disk failure.

No one should recommend RAID as a long term backup strategy, it should only be used as a short term backup to preserve file changes until you can make a real backup.

 

[Arcanedeath]

The current backup method you have I've found to be the most cost effective as long as you can fit all the data on a single drive. RAID isn't really for long term backup, it mostly just gets you more performance and as long as it's not raid 0 protection from 1 or more disk failures, Its more like hardware fault protection that a backup solution.

 

[bigshooter]

Raid 5 should be used as an added safeguard for your data, but it won't necessarily guard against everything. If you drive with your eyes closed, you'll probably hit something. If you drive with your eyes open you could still hit something, but the chances are a lot less. RAID will give you this. People tell you not to use it for backup, but if you have quality hardware, the chance of losing your entire array is pretty low, a lot lower than losing just the controller or one of the drives. If you are going to lose money if this data is lost then you need to get a tape backup or some other sort of archiving solution. If you just want something to store anime and porn on then this would be a good bet.

BTW: if this is just media like movie and mp3's then archiving to dvd would be a cost effective idea. My roommate works at best buy and just got me 500 4x dvd+r's for $60. At 4x it would take you 450 minutes to burn all your data, so other than about $5-$10 your only other investment would be 8 hours of time. It really depends on what you are backing up.

 

[deveraux]

Ok, thanks for the input guys! I guess I'll just go with an external hard drive and just get a Raptor. Will save a lot on cost as well.

 

[jvarszegi]

Good luck backing up your 120GB onto a 74GB Raptor. :disgust: Dumbest strategy I ever saw.

 

[Jeff7]

Originally posted by: bigshooter
Raid 5 should be used as an added safeguard for your data, but it won't necessarily guard against everything. If you drive with your eyes closed, you'll probably hit something. If you drive with your eyes open you could still hit something, but the chances are a lot less. RAID will give you this. People tell you not to use it for backup, but if you have quality hardware, the chance of losing your entire array is pretty low, a lot lower than losing just the controller or one of the drives. If you are going to lose money if this data is lost then you need to get a tape backup or some other sort of archiving solution. If you just want something to store anime and porn on then this would be a good bet.

BTW: if this is just media like movie and mp3's then archiving to dvd would be a cost effective idea. My roommate works at best buy and just got me 500 4x dvd+r's for $60. At 4x it would take you 450 minutes to burn all your data, so other than about $5-$10 your only other investment would be 8 hours of time. It really depends on what you are backing up.

I'm still not quite clear on why RAID 5 isn't a good idea. The chance of losing the array is fairly low - you need two drives to die at the same time. If the controller dies, I'd think that you should be able to get another controller and get your data off.
The biggest concern I'd have would be a power surge - entire PC dies. Granted, you can still send the drives to a data recovery center, but that'll cost you something grand, like maybe several grand.

My RAID 5 setup has been working wonderfully, courtesy of a Promise SX4000 card. I recently upgraded the drives in it, one at a time. Each reboot, the array automatically recognizes the new drive, and synchronizes the data across it, though the extra space remains unallocated - you need a partition program to use it, or else re-create the array.
But it still is working wonderfully; I back up my main PC, and all the computers on the network (two others) to the array every night.
I would like to see what happens when a drive actually fails; I've only seen what happens when one is unplugged. The array still boots, but just shows a warning, and it runs a bit slower.

But, as was said, a single drive solution is considerably cheaper; I've got nearly $1000 in this array - 4 200GB drives, plus the SX4000.

 

[DaveSimmons]

Originally posted by: Jeff7
I'm still not quite clear on why RAID 5 isn't a good idea. The chance of losing the array is fairly low - you need two drives to die at the same time. If the controller dies, I'd think that you should be able to get another controller and get your data off.
The biggest concern I'd have would be a power surge - entire PC dies. Granted, you can still send the drives to a data recovery center, but that'll cost you something grand, like maybe several grand.

RAID5 (or 1 for most people) is a good supplement to a real backup strategy but only offers protection against one kind of data loss: disk failure.

You can lose data from disk failure, other hardware failure (motherboard, PSU), virus / trojan / worm, other software problem, human error (deleting wrong file/folder), fire, flood, theft, powerline problem.

 

[chasem]

i've been using a raid5 solution w/ 6 80 gig IDE drives for about 3 years now. I've had one disk die, and it rebuilt fine. I know it doesn't help me against trojan/worm etc, but i cover stuff like that w/ other things. BUt then again, its mp3s and movies, not my finacial history. Any pictures of family or me, i have burnt in multiple places

 

[deveraux]

Originally posted by: jvarszegi
Good luck backing up your 120GB onto a 74GB Raptor. :disgust: Dumbest strategy I ever saw.

Err ..ok, I kind of meant using the external hard drive as a backup and using the raptor as my main drive for performance since I'll save money on the RAID controller + extra drives.

 

[Jeff7]

Originally posted by: DaveSimmons

Originally posted by: Jeff7
I'm still not quite clear on why RAID 5 isn't a good idea. The chance of losing the array is fairly low - you need two drives to die at the same time. If the controller dies, I'd think that you should be able to get another controller and get your data off.
The biggest concern I'd have would be a power surge - entire PC dies. Granted, you can still send the drives to a data recovery center, but that'll cost you something grand, like maybe several grand.

RAID5 (or 1 for most people) is a good supplement to a real backup strategy but only offers protection against one kind of data loss: disk failure.

You can lose data from disk failure, other hardware failure (motherboard, PSU), virus / trojan / worm, other software problem, human error (deleting wrong file/folder), fire, flood, theft, powerline problem.

True. Of course, adequately armed, it's possible to protect against a few of them:
Rstudio can recover from deleting the wrong stuff (done it), and possibly from viruses, depending on how thoroughly they do their jobs. And software problems, it might be able to take care of.
Things like fire, floods - you're dealing with a major loss then. I'd expect that data loss isn't going to be on your mind then.

And, after some fiasco awhile ago - reading about people's CD-R's starting to flake apart after only a year or two, and experiencing it in person - I've lost some faith in the "30-100 year shelf life" of recordable discs.
I do still have some DVD+RW's around for storing software that I've paid for, and other REALLY important stuff. That way, if something really bad happens, I'll have the important stuff safe enough.

Originally posted by: deveraux

Originally posted by: jvarszegi
Good luck backing up your 120GB onto a 74GB Raptor. :disgust: Dumbest strategy I ever saw.

Err ..ok, I kind of meant using the external hard drive as a backup and using the raptor as my main drive for performance since I'll save money on the RAID controller + extra drives.

Jvarszegi: There's this wonderful thing called "data compression." That can be quite useful.
I use WinRAR when I can - it has better compression abilities than ZIP, and it also lets you have a checksum, anywhere from 0% to 10% to help you recover data from a file damaged by a bad sector or scratched disc.
And I liked WinRAR so much, that I actually bought it!! Yes, believe it or not, I paid for software!

 

[jvarszegi]

Originally posted by: Jeff7

Originally posted by: DaveSimmons

Originally posted by: Jeff7
I'm still not quite clear on why RAID 5 isn't a good idea. The chance of losing the array is fairly low - you need two drives to die at the same time. If the controller dies, I'd think that you should be able to get another controller and get your data off.
The biggest concern I'd have would be a power surge - entire PC dies. Granted, you can still send the drives to a data recovery center, but that'll cost you something grand, like maybe several grand.

RAID5 (or 1 for most people) is a good supplement to a real backup strategy but only offers protection against one kind of data loss: disk failure.

You can lose data from disk failure, other hardware failure (motherboard, PSU), virus / trojan / worm, other software problem, human error (deleting wrong file/folder), fire, flood, theft, powerline problem.

True. Of course, adequately armed, it's possible to protect against a few of them:
Rstudio can recover from deleting the wrong stuff (done it), and possibly from viruses, depending on how thoroughly they do their jobs. And software problems, it might be able to take care of.
Things like fire, floods - you're dealing with a major loss then. I'd expect that data loss isn't going to be on your mind then.

And, after some fiasco awhile ago - reading about people's CD-R's starting to flake apart after only a year or two, and experiencing it in person - I've lost some faith in the "30-100 year shelf life" of recordable discs.
I do still have some DVD+RW's around for storing software that I've paid for, and other REALLY important stuff. That way, if something really bad happens, I'll have the important stuff safe enough.

Originally posted by: deveraux

Originally posted by: jvarszegi
Good luck backing up your 120GB onto a 74GB Raptor. :disgust: Dumbest strategy I ever saw.

Err ..ok, I kind of meant using the external hard drive as a backup and using the raptor as my main drive for performance since I'll save money on the RAID controller + extra drives.

Jvarszegi: There's this wonderful thing called "data compression." That can be quite useful.
I use WinRAR when I can - it has better compression abilities than ZIP, and it also lets you have a checksum, anywhere from 0% to 10% to help you recover data from a file damaged by a bad sector or scratched disc.
And I liked WinRAR so much, that I actually bought it!! Yes, believe it or not, I paid for software!

My snotty tone deserved a snotty response, so I'm okay with that. Honestly, though, I think anyone who has lots of data to back up would be stupid to compress it. Ever had a large compression/decompression fail? I also have a copy of WinRAR. It's not foolproof, although it beats the hell out of Winzip for sure!

 

[jvarszegi]

Originally posted by: deveraux

Originally posted by: jvarszegi
Good luck backing up your 120GB onto a 74GB Raptor. :disgust: Dumbest strategy I ever saw.

Err ..ok, I kind of meant using the external hard drive as a backup and using the raptor as my main drive for performance since I'll save money on the RAID controller + extra drives.

I apologize, sincerely. That's the most sensible thing anyone's said yet. Honestly, if I were to use RAID 5, it would always be to make sure that I had up-to-the-second data security, and I'd only use it if RAID 1 didn't offer enough space for the money. If I used RAID 5, I'd use a cheaper tape or disk to do backups, since the data would be more secure in the first place.