There is a problem when creating a software RAID 5 volume:
After creating a RAID 5 volume and rebooting the PC (the first time after creating the volume), the RAID 5 volume can be broken.
For create a 'stable' RAID 5 volume:
- Format your RAID5 volume twice (but using the Web GUI)
- Put a small file on this volume
- Reboot the PC
- Check that the volume is correctly mounted and working.
If not: re-format the volume,reboot and re-check.
I can reproduce this problem and send an email to the gvinum devel mailing list.
FreeNAS main developer