> So I try a 'legacy' approach per the cryptosetup wiki:
>
> linux-p22i /root# cryptsetup create back5 /dev/sdi1
> Enter passphrase:
> (which I did; just got newline)
>
> linux-p22i /root# cryptsetup status back5
> /dev/mapper/back5 is active.
>   type:    PLAIN
>   cipher:  aes-cbc-essiv:sha256
>   keysize: 256 bits
>   device:  /dev/sdi1
>   offset:  0 sectors
>   size:    976768002 sectors
>   mode:    read/write
>
> ***which seems correct to me***
>
> linux-p22i /root# l /dev/mapper/
> back5@
> cr_ata-WDC_WD1002FAEX-00Z3A0_WD-WCATRC268610-part1@
> control%                                            main@
>
> Now. How do I or what do I mount?  I can't use /dev/mapper directly.
> I have no success trying to mkfs /dev/back5.
>
> This must be a common problem but I don't find
> it addressed in the opensuse forums.
>
>
The mapper path created is "/dev/mapper/back5".This is the plain text path
you use to access stuff stored in the encrypted volume.

Just to be safe the default options of cryptsetup are the same as the ones
you used when you were using losetup,run the following commands to see if
they will recognize the file system on the volume.

blkid /dev/mapper/back5

what seem correct to you may not be.With slightly different encryption
options,its even possible for blkid among other tools to see valid file
system giving you more hope you have used correct options and you could end
up corrupting your data if you write to them.

I think the safety thing to do is to go back to an old system where the
volumes worked,copy the data off of them and then create a new cryptsetup
volume on the device and then move back your data.