Thanks. I move it to the appropriate community.

Further more

1.how do I figer it out after creating RG?

2.is the utilization of this prarity disk higher than others dsiks in same RG?

Review the KB article referenced above.  It will explain how to determine it also after RAID Group creation.

I don't have an old array (version of FLARE) running that supports RAID 3 to test, however, I would assume if you ran the "getrg" command, it would correspond to the first disk listed.  Do you have the ability to try?  Create a RG per the kb article, then compare it to the navicli "getrg" output.

I don't have array to try either, but I will find one to try and get back here.

Do you have any hint about my second question?

Take a R3 4+1 - four disks are used for data and one disk is used for parity. Each disk is formatted at 64KB, so that with four disks you have a stripe size of 4 * 64KB = 256KB. If you write one 256KB block of data to the disk, you will change the data on each of the disks and then calculate Parity and write that to the Parity disks. You need to think about this one. If the data resides on the four data disks and you write new data to the raid group that is 64KB in size, do you update the Parity disk?

glen

hi Glen

does that mean the parity disk always needs to write parity whatever the write data samller or full stripe? and this makes parity disk always much busy than others...

hi Christopher:

I tried to create RAID3 group, and list disks by CLI(getrg). It's true the first listed disk is the one I choose first in GUI.

It is not listed by disk number sequence.

Whenever you change the data on the disks (write) the parity also needs to be updated. For every write, so yes, the parity disk will sometime show more IOPS than the other disks.That is normal.

glen