As a followup, I reformatted the drive in RAID-1 and ext3 to be sure of the setup. When the formatting completes the web page updates showing a confirmation page that the setup was done as RAID-1/ext3. Once you navigate away from that page the filesystem type is no longer visible so pay attention.
As a side note I did see some inconsistency in the admin screens, particularly on the Tools->RAID screen. At one point all the buttons were grayed out so I could not select option to set RAID configuration and rebuild. A little while later after logout/login the option was available and everything worked fine.
I suspect it was a side-effect of either 1) earlier navigating through this page, selecting button to set RAID but not following through as not wanting to format, or 2) under Tools->Disk_Diagnostic I tried to run an extended test on one of the drives (in a final attempt to see if that would display the file system type), during which the test was aborted for some unknown reason (might have been due to the default 10 minute Admin inactivity logout, I have no idea). All the other screens seemed to be fine during this time.