Running 3 Parity drives

[Melocco]

I know this might be a stupid question, But I can not find an answer to the question..    Can I run three Parity drives on unraid? Reason I am asking is that some of the drives I am using are old and I do have at least a single replacement drive incase a drive fails, but I was thinking about this summer when I go on vacation and am not here..   

 

I would feel safer if I could run an additional parity. I'm kinda a hoarder or worry wart, what ever you want to call me. I have everything on the unraid, backed up on external drives and extra drives I've taken to someone that lives out of state and two APC battery Backups connected. But I just wanted to be safe..  I tried adding the extra drive but can't seem to figure out how to add another parity drive. I have two new dives set as parity now..  

 

Am I overlooking something or am I just out of luck? Thanks in advance..  

[itimpi]

No - only two parity drives are supported.   Whether this will ever be increased i have no idea - it was not that long ago that the option for the second parity drive was added.

[pwm]

1 hour ago, itimpi said:

No - only two parity drives are supported.   Whether this will ever be increased i have no idea - it was not that long ago that the option for the second parity drive was added.

A second parity drive makes a lot of sense.

A third parity drive gives very little additional advantages for unRAID - it's more important for traditional RAID:

 

For LT, it would be more meaningful to either add support for multiple arrays or add checksum functionality.

 

Another thing to consider - for unRAID it would be more appropriate to have new data disks than to have new parity disks.

 

If drives dies, then every single disk is as important for computing the content of the lost drive(s). But if the system has n parity disks and n+1 disks happens to die, then you would prefer that all parity disks are among the failures because then you would only lose the content of one data disk. When n+1 disks dies and none is a parity disk, then it's the content of n+1 data disks that will be lost.

 

So you should always think twice about depending on really tired data disks.

[Melocco]

Thanks for the reply's. I am just going to stick with the two now and hope they may add it later. I wouldn't use older drives, but I don't want to spend a fortune on new drives if the others are still running..  I am running 36tb of room with two new 4tb ironwolf pro drives as parity. If I had to replace all those drives, it'd cost more than I want to spend. 

 

Atleast it's still running and having no issues. If the S.M.A.R.T. picks up any issues, I will replace them as needed..  Thanks again for responding.