Hi,

 

It's a new set up so all my disks will have been formatted by Unraid.

 

Is it normal for an empty array to take like 5 hours to make the parity disk?

The largest HDD is 4TB so the parity HD is a 4TB. 5400RPM.

 

 

Should take even longer?

 

4TB in 5 hours on a 5400RPM seems impossibly fast to me, my 4TB reds take about 12 hours. Empty or not has no effect on parity creation speed, it still has to read/write the entire disks.

ok, thanks. As long as it's all normal I'm ok with it.

 

I was not sure if parity would take long on empty disks.

 

Thanks for your reply !

 

ok, thanks. As long as it's all normal I'm ok with it.

 

I was not sure if parity would take long on empty disks.

 

Thanks for your reply !

Parity Creation / Checking / Drive Rebuilding works on the disk level, not on the file level, so they always take hours even on completely empty arrays.

 

But I'm in agreement that 5hours for 6tb does seem fast.

Yer I went and checked when I read his post. I'd read the screen wrong. It was 5 hours left. It had already been running 4 hrs at that point.

 

The speed will also slow down as the drive nears the inner cylinders, so it'll likely take even longer than the 5 hours you noted -- but even 10 hours or so is a very good time for a parity sync.

 

Note that there's no such thing as an "empty" disk => the file system can be empty (i.e. no data), but the disk itself always contains 1's and 0's => and that's what the parity is calculated on.    So a parity sync or parity check will take exactly the same amount of time regardless of whether it's an empty file system or a disk completely full of data.

 

And another point perhaps implied but not explicitly mentioned by others:

 

Your subject line says 6TB but then you mention 4TB parity. Parity build or check speed is mostly about the size of the parity disk, not the amount of total storage because all disks will be used in parallel. It is possible to have some bottlenecks caused by your particular hardware that could prevent all drives being accessed simultaneously, but this doesn't sound like anything you are likely to have with your small number of disks.