I am comfused

[mindaugas]

Got terrastation 4400 with 4 drives. Chose RAID 10. After update it is shown, that I  am using RAID 0 and no option for RAID 10:

"Easy Admin > RAID Settings

Select your desired RAID mode.

Current RAID:
Disk 1, 2, 3, 4 RAID0 (Capacity: 10.8TB)
　　　　
Combine multiple drives into an array. Usable capacity will be the total of all drives. If any hard drive crashes, all data will be lost.
RAID0
Combine multiple drives into an array. Usable capacity will be the total of all drives. If any hard drive crashes, all data will be lost.
RAID1
Combine multiple drives into an array. Usable capacity will be one drive's. If any hard drive crashes, all data can be recovered.
RAID5
Combines 3 or more drives into a single array. Write speeds will be slower than a single drive. The usable capacity of the array will be the total of all the drives minus one. If any single drive crashes, all data can be recovered. If 2 or more drives crash, the data is lost.
RAID6
Combines 4 or more drives into a single array. Write speeds will be slower than a single drive. The usable capacity of the array will be the total of all the drives minus two. If one or two drives crash, all data can be recovered. If 3 or more drives crash, the data may be lost.
If you change the RAID mode, all data on the drives will be lost.

"

There is RAID 10 ?

while the  documentation:

"To use a hot spare, you need an extra drive that's not part of any array and a RAID 1, RAID 10, RAID 5, RAID 51, or RAID 6 array."