Purposely Duplicating Data in An Array

[kizer]

Does anybody see any problems with purposely having a drive or two in the array that has the same data on it for an internal backup? Meaning something of the sort like this.

 

Disk1 Movies - Share Name Movies

Disk2 Tv shows - Share Name Tv

Disk3 Mp3 - Share name Mp3

Disk4 Private files - Share Name -Misc

Disk5 Private files(Copy from Disk4) - Share Name Misc-copy

 

My thought is if I loose disk4 for any reason I can easily rebuild with the parity, but if I had a failure beyond Disk4 and the pairty at the sametime I would at least have a copy.

 

The only thing I can think of is the system would note that there are files of the samething. Could use use different shares to get around?

 

My thought process was to reduce having 2 servers and dupicate what I have internally if/when it made sense.

 

Thoughts, Problems?

[Rajahal]

Yes, that will work fine.  You can even have them in the same share if you like, since unRAID will just ignore the second file (misc-copy).  They won't be synced though - any changes you make to the first file will have to be manually copied over to the second file.  Look into rsync if you want this done automatically.

 

The only problem that I see with this is that you still aren't protected from a two disk failure if you happen to lose both disk4 and disk5.  Still, I think it is a good idea, especially if your private files are relatively small.

[kizer]

Yes very true. I'm just thinking the chances of loosing my data drive and my parity drive are slim as it is, but to loose both of my data drives and the pairty are even slimmer.

 

 

[graywolf]

Yes very true. I'm just thinking the chances of loosing my data drive and my parity drive are slim as it is, but to loose both of my data drives and the pairty are even slimmer.

 

You wouldn't need to lose both data drives AND the parity drive. Once you lose 2 drives, parity will not work.

So really, what you are figuring is the odds of losing 2 specify drives at the same time.

In which case, you could always make your important file share across all data drives and copy it on all drives for duplication....just depends upon how crazy redundant you want to get.

 

Of course even that wouldn't save you from fire, flood, lightning strikes, theft, etc.

 

 

[rharvey]

I do something kinda like this for my vast collection of music.  When I first got my unRaid I was not well versed enough to understand all the little nuances of the box when things would go wrong, and they often did because I used a lot of old IDE drives in the first box.  Long story short I lost a lot of music on fateful day.  So now I have one share that I consider my "master" music share and then on another physical drive I have an exact copy of the "master".  I keep them in sync with a little application called Second Copy which I have running on a Windows server that runs 24x7.  I drop any new music into the "master" share and each night the new stuff get copied into the backup location.  Overkill, well maybe but I'm only using up another 100g of space to be very safe.

[queeg]

Doing periodic backups to store offline is a good plan.  One of the primary reasons I made SNAP was to help make backups a bit easier.  Stick in a drive and it runs an event that can sync data to or from the array.  I like my server to remember the rules by identifying the hardware (drive) and that way I don't make mistakes when I'm in a hurry.  After adding the drive and the program code to SNAP it's a no brainer. 

[kizer]

I haven't implemented a offline backup as of yet, but I'm thinking of using a Toaster Style NAS that I have either in the garage or away from my other machine just in case there is a fire, flood or other act of god. Its currently off, but does contain a lot of what I have been putting on my unRAID setup.

 

I still think I might implement another drive in the array to make a copy of important data that is on hand