Whether the 10T NL-SAS disk can do raid_dp, I see that 9.9.1P10 seems to support 10THDD to do raid_D

[nice]

Whether the 10T NL-SAS disk can do raid_dp, I see that 9.9.1P10 seems to support 10THDD to do raid_DP

[TMACMD]

I think this falls into one of my catch phrases:

 just because you >can< doesn’t mean you >should<

A 10T drive in some cases can take many hours to  a day or more to rebuild. There is extra activity to verify data to be rebuilt. Losing one drive (DP) you can still recover. Losing  two during rebuild may  cause data loss. 

engineering put RAID TEC as the default on large drives for one or more reasons. 

[paul_stejskal]

Because it takes days (or can in more extreme circumstances) to rebuild a single drive, 3 is better than 2 when you get that large in spinning media capacity.