# TECHHow much damage can raid 10 take

#### DigiCrime

##### If Only!
Just curious. Depends on the scenario I know but if you have two drives fail on a mirror, then the array is lost yes? Works somewhat like Raid 0 (two drives but if one is lost the array is shot) so in raid 10 it can sustain only a two drive failure. Correct?

#### deusexaethera

OT Supporter
It depends on the structure of each array. If it's two RAID 0 arrays mirrored together, you can lose up to one drive (which will cause one of the two arrays to fail). If it's two RAID 3/4/5 arrays mirrored together, you can lose up to two drives (which will cause one of the arrays to fail). If it's two RAID 6 arrays mirrored together, you can lose up to three drives (which will cause one of the arrays to fail). If it's two RAID1 arrays mirrored together (i.e. a 4-way mirror), only one drive has to survive. Additional arrays added to the mirror will increase the number of failed arrays that can be tolerated before the data goes poof.

Basically it's something nobody will ever need for personal use unless they take their computer off-roading with them, in which case they might as well just buy SSDs and never have to worry about vibration-related failure again.

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#### DigiCrime

##### If Only!
I was correct on my original answer yesterday when I was asked. I said it depends on how your array is setup but my question was vague it just asked how much damage can a raid 10 take?. I put down in a RAID 1 configuration you can loose three failed drives.

#### White Stormy

##### Take that, subspace!
It depends on how many drives are in the array...

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#### DigiCrime

##### If Only!
It depends on how many drives are in the array...

I was taking a test for a network engineer opening. It just asked how much damage can a RAID10 sustain

It was doing my head in pretty sure I will fail that question because I didnt explain it to it's fullest. I was thinking along the lines if yo have four drives, two arrays doing raid 1 you can only sustain two drive failures, but if all four are mirroring in raid 1 you can fail three drives. It was confusing the more I had thought about it.

#### XR250rdr

OT Supporter
With 2 striped mirrors you can lose one drive per mirror.