[bjmarchini]

I have a server as many here do. It stores my music, pictures, personal documents, and back up ISOs of my software (such as games and utilities).


It is also used as a media server as well for movies. I have been adding movies to the server and will increase the capacity from 1TB to 2 TB within a few months. I only plan to keep about 100-150 movies on the server at most.


Here is the thing. The first group of items total about 100GB plus another maybe 100gb at most for the ISOs though that will increase over time. Those I want to keep archived. I could care less about the movies as I tend to skim them from time to time and I have a back up anyway of each of them (the original disks - I have another 200-300 that I am not going to bother loading for my own reasons).


SO, a dedicated raid solution, like flexraid or unraid, would probably work except for two reasons: I don't want to waste the space backing up the movies and (this is the kicker) it is often used as a dedicated game server.


The dedicated game server is the kicker. If it wasn't for that, I would think WHS would be perfect.... but it isn't.


The three solutions that I am looking at now is a simple autobackup program that I got off zdnet, Nero Back it up or simply files manually to a back up folder on a seperate disk.


An other thoughts. I did some looking at dynamic disks, apparently mirroring is not supported in XP pro.

 

[stanger89]

FlexRAID isn't a dedicated RAID solution, it's a parity creation/RAID snapshot app you run on your PC on whatever folders you want to use.


Anyway, soapbox time:


It sounds like most of what you're trying to protect is irreplaceable data, or at least difficult to replace. RAID, or any other online parity/mirroring system is not backup, it's not a substitute for backup, at most it's a supplement to backup.


Solutions for backup are things like burning to optical discs, copying it to a usually disconnected hard drive, off site/online storage, etc. Basically anything that can't/won't be taken out by or with your computer.

 

[Nosferax]

When I buy a new HDD to add to my HTPC I also buy an external one of the same size as a backup. I use SecondCopy once a week to sync the externals and externals (incremential backup).

 

[bjmarchini]



Quote:
Originally Posted by stanger89 /forum/post/16878070


FlexRAID isn't a dedicated RAID solution, it's a parity creation/RAID snapshot app you run on your PC on whatever folders you want to use.


Anyway, soapbox time:


It sounds like most of what you're trying to protect is irreplaceable data, or at least difficult to replace. RAID, or any other online parity/mirroring system is not backup, it's not a substitute for backup, at most it's a supplement to backup.


Solutions for backup are things like burning to optical discs, copying it to a usually disconnected hard drive, off site/online storage, etc. Basically anything that can't/won't be taken out by or with your computer.

I understand RAID. There are many types of RAID. There is striped RAID 0 which is geared for performance. There is spanned RAID which is design to ease the upgrading of storage. And then there is mirrored RAID 1. AND YES, mirrored is designed as a back up solution.


When I was new, I constantly heard little soapbox speaches about how raid is not a back up solution. In actually mirrored RAID IS a very good back solution as it is live and doesn't wait for a back up procedure to start.


Why else would someone use mirrored Raid? It is going to use more resources and reduce overall performance unlike striped RAID. Striped RAID is the opposite where is say the heck with archival needs, we are going all performance. RAID 3 through 5 were to help bring sanity back to a performance RAID system (performance sounds great til you lose data).


And then there is RAID 6 which has 2 parity drives. why? Because it is designed for even better fault tolerance.


I am not saying that RAID was solely designed for a back up solution. It wasn't. But it was one of intended uses.

Quote:
Originally Posted by Nosferax /forum/post/16878306


When I buy a new HDD to add to my HTPC I also buy an external one of the same size as a backup. I use SecondCopy once a week to sync the externals and externals (incremential backup).

Interesting idea. Another solution might even be to put an extra XXXgb hard drive on my bedroom desktop and set it up to back it up from time to time. It would readily, and easily, accessible if the server did go down for whatever reason. I could even assign the bedroom desktop as a compressed drive to help save space.

 

[stanger89]



Quote:
Originally Posted by bjmarchini /forum/post/16881649


...YES, mirrored is designed as a back up solution.


Why else would someone use mirrored Raid?

RAID (levels 1+) is fault tolerance, not backup. There is a difference. RAID (1+) is designed to do one thing, and one thing only, protect your data in the event of a disk failure.


RAID is used for two primary purposes:

• To keep critical systems running in the event of a disk failure
• To reduce the risk of downtime/rework for data lost to a disk failure between backups

Both of them are only protection from disk failure.


Backup is essential in addition to RAID for any irreplaceable data. RAID doesn't protect your data from stupid users (accidental modification/deletion), a backup does. RAID doesn't protect your data from malicious entities (viruses, etc), a backup does. RAID doesn't protect your data from software failures, a backup does.


What happens if you go to upgrade to Win 7 and accidentally repartition/format your RAID array. You're SOL. If you had that data backed up somewhere, you could recover it.


What happens if your kid/friend/etc downloads a new cool game and it wipes your computer. RAID = SOL. Backup = recovery.


What happens if lightning strikes your house and fries all your computers/HDDs that are plugged in (eg if it sneaks in through the lan/phone or something you forgot to protect). RAID = SOL, Backup = recovery.

Quote:
And then there is RAID 6 which has 2 parity drives. why? Because it is designed for even better fault tolerance.

Exactly, fault tolerance not backup.

Quote:
I am not saying that RAID was solely designed for a back up solution. It wasn't. But it was one of intended uses.

RAID may be part of a backup strategy, but it is not backup in and of itself. A good example is WHS. WHS uses folder duplication for fault tolerance. WHS also provides backup capabilities, but the way WHS fits into a backup strategy is it duplicates other PC's content onto itself, thus creating two copies on two machines. This way if you accidentally delete your favorite picture of your pet off your main machine, you can recover it by grabbing the backup.


RAID/fault tolerance is enough to keep you from having to re-rip your DVDs in the event of an HDD failure, or restore your backup of your irreplaceable data. But it's very important to understand it's limitations are, and those are that it only protects from a disk failure.


There are lots of other ways to destroy data (natural disasters, user error, malicious entities, etc). I would never trust my digital photos or personal documents to RAID alone.


I keep then on a redundant array yes, but I also keep them on another machine, and I periodically burn them to DVD.


At work, we have many levels of fault tolerance/backup. All the network storage is on some sort of RAID (I assume), to keep it online in the event of a disk failure. In addition, every few hours a shadow copy is made, and a few days worth of those copies are kept around. This way if someone accidentally deletes an important folder (which happens with disturbing frequency), it's easy to recover that data (RAID wouldn't help there). And beyond that, all that data is archived/backed up to tape as the old shadow copies are replaced by new ones. So if something important got lost and nobody realized it right away, it can be recovered from the tape backup (this has also been necessary).


It's fine if you want to trust your photos, home movies, and personal documents to only RAID/redundancy protection. But it doesn't change the fact that RAID/redundancy is no substitute for a true disconnected, isolated backup. Like you said in your OP, your DVDs are already backed up by nature of you having the original disks. The same is not true of your photos and personal documents.


You really should have some plan to periodically burn them to optical media, copy them to a normally disconnected HDD, or even upload them to an online backup service.


Or to put it another way. Based on what you want to protect, the amount and type of data, I wouldn't even bother with RAID/redundancy/fault tolerance. Just setup a good backup strategy, copying to another machine, copying to DVD periodically, etc.

 

[miimura]



Quote:
Originally Posted by bjmarchini /forum/post/16881649


I understand RAID. There are many types of RAID. There is striped RAID 0 which is geared for performance. There is spanned RAID which is design to ease the upgrading of storage. And then there is mirrored RAID 1. AND YES, mirrored is designed as a back up solution.


When I was new, I constantly heard little soapbox speaches about how raid is not a back up solution. In actually mirrored RAID IS a very good back solution as it is live and doesn't wait for a back up procedure to start.


Why else would someone use mirrored Raid? It is going to use more resources and reduce overall performance unlike striped RAID. Striped RAID is the opposite where is say the heck with archival needs, we are going all performance. RAID 3 through 5 were to help bring sanity back to a performance RAID system (performance sounds great til you lose data).


And then there is RAID 6 which has 2 parity drives. why? Because it is designed for even better fault tolerance.


I am not saying that RAID was solely designed for a back up solution. It wasn't. But it was one of intended uses.




Interesting idea. Another solution might even be to put an extra XXXgb hard drive on my bedroom desktop and set it up to back it up from time to time. It would readily, and easily, accessible if the server did go down for whatever reason. I could even assign the bedroom desktop as a compressed drive to help save space.

I have to strongly disagree with you about mirroring being backup. The real reason for using mirroring is availability. If you mirror your system disk, the system will keep running if one disk fails. Therefore, the system is always "available". The main reason why it is NOT backup is that if you accidentally delete a file on a mirror set, it's gone. If it was a backup, it would not be gone. Period.


- Mike

 

[bjmarchini]

And why does a back up solution require that it NOT be readily available? I think what we are conjecturing here is a matter of symantecs.

 

[vladd]

Both systems are "backups" but for two completely different objectives.


Mirrored RAID is a backup in case of hardware disc failure in order to reduce downtime and increase availability.


Offsite/Offline backups (disconnected drive, remote ftp, optical and magnetic media, etc) are backups in case of data loss.


It's up to you what type of protection you need. Using both provides the most complete protection.

 

[stanger89]



Quote:
Originally Posted by bjmarchini /forum/post/16885192


And why does a back up solution require that it NOT be readily available? I think what we are conjecturing here is a matter of symantecs.

Depends on what you mean by "readily available". If you mean "live" or "realtime" like in RAID, the reason is because live/realtime duplication/redundancy can't protect against user/software failures. If a file is deleted, the realtime duplication/redundancy will immediately duplicate that deletion, and that file is gone, period. If you need it back because that wasn't the file you thought you were deleting, too bad, it's gone.

Backup is a type of redundancy that protects against things like this, accidentally deleted files, etc. And it therefore by definition must not be real time.

 

[stanger89]



Quote:
Originally Posted by vladd /forum/post/16885218


Both systems are "backups" but for two completely different objectives.

I disagree. Both systems are redunancy but realtime (parity/mirroring) and non-realtime ("backup") redundancy are very different things.


Here's why I disagree with calling both backup. I think most people are at least somewhat aware that their data is not "safe" when it's only stored on their computer. They understand that hardware failure or viruses, or other things could kill their data.


People understand that they should "back up" their data to protect it. What most people don't understand is that there are different types of redundancy that they protect from different things.


I agree completely with your descriptions of what the types of redundancy do, and those definitions are why I think we shouldn't call both "backup". Because calling RAID and other realtime, connected redundancy schemes will give people like the OP the false impression that they protect against data loss.


"Backup" is a form of redundancy, but that does not mean all forms of redundancy qualify as "backup". The real fundamental principal is that "backups" allow you to go back to a previous state and recover data. RAID and other live/realtime redundancy schemes only protect the current state.


This is actually a pretty good article about the various types of backup:
http://en.wikipedia.org/wiki/Backup


Consider a Mac. You could have RAID in a Mac, that would keep the system running and prevent data loss in the event of a disk failure. But Macs also offer Time Machine, which is a backup in that it allows for recovery of lost data.


I guess that's maybe the most concise explanation:

RAID/live/realtime redundance = prevention of data loss from a disk failure
Backup = recovery from data loss from any cause

 

[vladd]

stranger89, I completely agree. That's why I put the term "backup" in quotes. I'm just used to having to explain to clients in the simplest terms possible.

"Redundancy" is the correct technical term however. Just dont get me started on Time Machine, I just finished repairing an OSX server from an issue caused by Time Machine.