I have set up a raid6 array with 6 x 1TB WD HDDs - 4 of them are WD Greens and 2 of them are WD Reds.
Before setting up the array I had completely wiped them with dban. Without taking any further action (I was under the impression I did not need to) I added them all in the Raid6 array through the webui. The array was created ok, I created shares etc - everything seemed to work.
I run write and read tests using dd and I got strange results - 40MB/s to 75MB/s for 10GB files. So I subsequently run fdisk and the results show that the 4 "greens", despite being 4k drives, are formatted as "older" type (512KB physical) while the 2 "reds" were correctly formatted as 4k drives (4096 physical)!!! I am attaching examples from the fdisk:
"Disk /dev/sdg: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000"
vs
"Disk /dev/sdf: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdf doesn't contain a valid partition table"
I am completely buffled ( 
) - why is this happening and how can I correct it? Is it possible that the drives report themselves (incorrectly) as 512KB physical??
I really want to fix this as I believe it is degrading my array's performance (and could be potentially dangerous for my data?) How can I specify to the OMV to treat them as Advanced Format?