Hi All,

 

 

I built a new server and added 12x8TB drives, 10 data and 2 parity.  They are all pre clearing simultaneously with no issue.

 

Specs:

 

ASRock C226M WS

Intel Celeron G1840 2.8GHz Dual-Core Processor

8 GB Ram

480 GB SSD Cache

12 x ST8000DM002 8TB 256MB Cache

 

I notice that some drives are faster than others, averaging from 112 MB/s up to 151 MB/s.  My question is, would there be any benefit to using the faster drives as the parity drives as they get written to the most?  

 

Once I'm done moving the data from my old machine to this new one I will replace the Celeron with the i7-4770 from the old machine.  Once the data is all moved over should i enable both parity drives at the same time or do I add one, let it sync and then add the other?

 

Thanks for your help,

 

Pajamas

 

I would suspect that the difference in speed may be related more to the Disk Controller hardware than any differences between the drives.

 

If you are going to be using that Core i7 CPU, there will be no difference in speed between single and dual parity.  The i7 has more than enough horsepower to both calculations faster than the write speed of the drives.  With that many brand-new data drives, I (personally) would be more comfortable with a dual parity setup when loading data on the drives.  (New hardware is far more likely to fail than the hardware with a couple of thousands hours of use.)

 

I would also suggest that you go to 'Settings', 'Disk Setting' and turn the "Reconstruct Write" on the ' Tunable (md_write_method):"  dropdown box.  This is will provide the maximum speed as you transfer your data to the new system.  The disadvantage is that all the drives will be spun up during writes but I feel that the increase in speed is well worth the increase in power consumption.  (I am assuming that you have many TB's of data to move so a cache drive would not buy you much.)