Hello,

i want to now what happen when the Parity drive crashes.

Is the whole RAID broken?

 

I read the section "unRAID Array" from

http://lime-technology.com/technology/

 

 

And what RAID type is the " Unraid Array" and how safe is it?

Thanks for helping

Hello,

i want to now what happen when the Parity drive crashes.

Is the whole RAID broken?

 

I read the section "unRAID Array" from

http://lime-technology.com/technology/

 

 

And what RAID type is the " Unraid Array" and how safe is it?

Thanks for helping

If you're running a single parity drive and any drive goes down, then you still have access to 100% of the information no problems

 

If you're running a dual parity system and up to two drives go down, then you will still have access to 100% of the information no problems

 

If the number of drives which go down exceeds the number of parity drives, then you will have lost some information, but unlike a tradition RAID system (where you will have lost all of the information stored), you will only loose the files that were stored on the excess drive that went down.

 

Which leads into your second question.

 

With single Parity, unRaid is kinda like RAID-4, but without the striping.  Same thing with dual parity.  RAID-5 but without the striping.  Not having the striping is IMHO a huge plus as no matter how many drives go down (and exceeds the number of parity drives) you will never lose all of your files.  Traditional raids if you exceed the number of failures that the system can handle you have lost all of your files.  unRaid you will only lose the files on the excess drive that went down

If you lose the parity drive, it's no different then losing any other drive.

 

With unRAID, you never lose the entire array.  So for instance, if you lost one drive (parity or data) all of your data would still be intact.  Let's say you lose two drives; you only lose the data on those two drives.  The others in the array would still be accessible and the data would be intact.  This makes it much better than a typical RAID 5 array in that regard.

 

Actually, if you were going to lose two drives, one of them being the parity would be the best case scenario, because that's means you are only losing one drive worth of actual data.

 

unRAID 6.2 also allows two parity drives, which means you could lose up to two drives without any data loss.

Thanks for these great answers!

You helped me a lot!

;D