I have converted my NasLite box to OMV using my old HDs formatted in ext3.
After configuring all the services, I have converted the drives from ext3 to ext4.
Here the steps i made:
-booted with PartedMagic Usb stick
-with GParted I have relabeled the 6 drives (they was all labeled with the same text string, making impossible to understand who was who)
-in a terminal I have issued the command (for example for sdb1):
then
-in the terminal i have modified the /etc/fstab file (for example for sdb1):
before
UUID=9e243565-16cd-4a6f-bc39-33fe98d33f55 /media/9e243565-16cd-4a6f-bc39-33fe98d33f55 ext3 defaults,nofail,acl,user_xattr,noexec,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0 0 2
after
UUID=9e243565-16cd-4a6f-bc39-33fe98d33f55 /media/9e243565-16cd-4a6f-bc39-33fe98d33f55 ext4 defaults,nofail,acl,user_xattr,noexec,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv0 0 2
-shutdown the system
-reboot in OMV and the drives in "Filesystem" should read now "Ext4" instead of "Ext3"
p.s.: if you modify the /etc/fstab from OMV just issue the command (only after you have modified the /etc/fstab file):