Thecus N2800 User Manual page 57

NOTE
Here is a list of limitation with RAID level migration function:
1. During RAID level migration, it is not permitted to reboot or shutdown
system.
2. For RAID migration from R1 to R5 or R1 to R6, all services will restart
and "iSCSI" volume will be in read only mode but read/write of the "user
data" will be possible during the operation.
NOTE
Migrating a RAID volume could take several hours to complete

The RAID migration feature is available only when it is configurable.

The migration scheme below is based on Thecus IP
Storage product's maximum possible combination.
For other model which supports less HDD, please
refer to the web UI while RAID migration operates.
57