Sorry if this has been asked before.  Dual parity just isn't enough with large arrays.  I've had to replace 2 disks a couple of times now, and having the extra peace of mind with that one extra disk would be amazing.

 

I know it's likely a big CPU overhead with the maths calculations, but if you could give people the choice, who have the hardware to do it, that would be amazing

 

Once you hit 14+ drives, the chance for an additional failure whilst rebuilding must skyrocket

 

thanks!

That is why many have requested support for multiple arrays within a single system.

That, and if it's so important you're willing to throw a 3rd party drive in the system, isn't it important enough to have a backup?

Easier said than done.  It's not easy to back up 100+TB of data

 

My important stuff is backed up according to the 321 strategy, but movies and tv shows which take up a huge amount of space can't easily be backed up.  Triple parity would at least give some additional peace of mind when swapping faulty disks. (it took some nagging to persuade my wife to let me but 14 x 14TB external drives!)

Edited February 20, 20206 yr by sdamaged

10 hours ago, BRiT said:

That is why many have requested support for multiple arrays within a single system.

That would also be pretty damn good!

I hear ya on 100+TB, but see the link in my sig.  My method will scale up to theoretically an infinite size for cold storage.

8 hours ago, sota said:

I hear ya on 100+TB, but see the link in my sig.  My method will scale up to theoretically an infinite size for cold storage.

@sota Link to sig?

Edited February 21, 20206 yr by sdamaged

5 hours ago, sdamaged said:

@sota Link to sig?

click on your name at the top of the forum, click on account settings, click on signature. The rest should be self explanatory.

Found it, thanks man.  Viewing other people signatures was disabled by default (never seen that before...)

Edited February 21, 20206 yr by sdamaged

nth parity seems like something that should be up to the user, so i'd vote for an nth parity option.  Is it more complicated programatically to add n vs 3?  Seems to be the best if it was uncapped and people can have between 0 and n if they wish.

 

ATM I'm happy with 2 but I can see why its a bit nerve racking if you have multiple SAS enclosures.

@spamalam That's actually a great idea.

I need it badly. 234 TB and 28 data drives with dual parity. I’d prefer multiple drive arrays, but will take anything I can get. I have multiple onsite, offsite, and cloud  backups of the most critical 14 TB of data, but that leaves a tremendous amount remaining. I’ve been adding to a second backup server over time and between the 2, having a FULL onsite backup we are quickly approaching 500 TB.

 

Finally, we run our media production company on UNRAID and high quality raw 4K footage is no joke space-wise. A single video project can be 1 TB by itself.

 

Looking forward to the future of UNRAID!

Apologies if it's against the rules to necro a thread but i'm adding a vote for a triple parity array.

 

I installed 2 brand new Toshiba 6TB drives into my array and both threw up errors. My VM's disappeared, Dockers crashed, everything ceased to function. I am currently biting my nails watching the array rebuild itself. I fear some of my older 8TB drives will give up during the rebuild.

 

Edited February 4, 20215 yr by LumpyCustard

Yep, triple parity would be nice. Whilst I have backups, it would have prevented losing some data, and prevented downtime today.

my understanding of finite fields is limited but i think the calculation for a nth parity would merely involve calculating disk number to the nth power in one.  not sure how much more overhead this would be than the 2nd power like it is now for dual parity.  if it isn't prohibitive i would like to be able to add a 3rd parity

Edited March 7, 20233 yr by duelistjp
needed more

+1. I am running 22 mostly 4TB data drives with overall 82T I also experienced dual drive failure for the second time recently. Surely a nail biting and nerve wrecking experience I do not want to go through again.

2 minutes ago, tazman said:

+1. I am running 22 mostly 4TB data drives with overall 82T I also experienced dual drive failure for the second time recently. Surely a nail biting and nerve wrecking experience I do not want to go through again.

Personally I think this is unlikely to happen as it provides marginal safety improvement as the chance of triple drive failure are so small that Limetech will probably not invest the development effort required.  When Unraid  6.13 arrives you could split your current array into 2 smaller ones each of which could then have dual parity.