Details about DASD disks (ECKD as well as FBAs) can be found in the 'Device Drivers, Features, and Commands on Ubuntu Server 18.04 LTS, SC34-2765' guide:
http://public.dhe.ibm.com/software/dw/linux390/docu/lub0dd01.pdf
(the 18.04 is the latest of these guides for Ubuntu - they are only created for LTS releases)

Here is a brief summary of all s390x-specific disk storage device types:

* zFCP (SCSI-over-Fibre Channel (FCP) devices and SCSI devices):
- lszdev | grep zfcp   # incl. zfcp-host (FCP devices) and zfcp-lun (zfcp-attached SCSI devices)
- can have up to 15 partitions
- partition with fdisk, parted, partman
- disk device type is just 'fba'
==> already supported

* DASDs in general (FICON-attached Direct Access Storage Devices):
- lsdasd shows both types (ECKD and FBA):
- lszdev shows both types (dasd-eckd and dasd-fba)

   * ECKD - Enhanced Count Key Data (ECKD) DASDs:
   - lszdev | grep dasd-eckd
   - label: msdos partition table
   - can hold up to 3 partitions
   - partition with fdasd
   - requires dasdfmt with disk device type 'cdl' (Compatible disk layout, 'ldl' is legacy and no longer in use)
   ==> already supported

   * FBA - Fixed Block Architecture (FBA) DASDs:
   - lszdev | grep dasd-fba
   - can hold up to 3 partition(s
   - partition with fdisk, parted, partman
   - disk device type is just 'fba' (here NO dasdfmt usage)
   ==> tbd

Identification/characteristics/tooling:

$ lsdasd 
Bus-ID    Status    Name      Device  Type         BlkSz  Size      Blocks
================================================================================
0.0.0101  active    dasda     94:0    FBA          512    16383MB   33554368
0.0.0300  active    dasdb     94:4    ECKD         4096   7042MB    1802880
0.0.0200  active    dasdc     94:8    ECKD         4096   7042MB    1802880
0.0.0400  active    dasdd     94:12   ECKD         4096   21128MB   5409000
0.0.0102  active    dasde     94:16   FBA          512    16383MB   33554368
0.0.0103  active    dasdf     94:20   FBA          512    16383MB   33554368
0.0.0104  active    dasdg     94:24   FBA          512    16384MB   33554592
$ lszdev dasd-eckd
TYPE       ID        ON   PERS  NAMES
dasd-eckd  0.0.0190  no   no    
dasd-eckd  0.0.0191  no   no    
dasd-eckd  0.0.019d  no   no    
dasd-eckd  0.0.019e  no   no    
dasd-eckd  0.0.0200  yes  yes   dasdc
dasd-eckd  0.0.0300  yes  yes   dasdb
dasd-eckd  0.0.0400  yes  yes   dasdd
dasd-eckd  0.0.0592  no   no    
dasd-eckd  0.0.1607  no   no    
$ lszdev dasd-fba
TYPE      ID        ON   PERS  NAMES
dasd-fba  0.0.0101  yes  yes   dasda
dasd-fba  0.0.0102  yes  yes   dasde
dasd-fba  0.0.0103  yes  yes   dasdf
dasd-fba  0.0.0104  yes  yes   dasdg
$ cat /sys/class/block/dasda/device/devtype 
9336/10
$ cat /sys/class/block/dasdb/device/devtype 
3390/0c
$ sudo dasdview -i /dev/dasda

--- general DASD information --------------------------------------------------
device node            : /dev/dasda
busid                  : 0.0.0101
type                   : FBA 
device type            : hex 9336  	dec 37686

--- DASD geometry -------------------------------------------------------------
number of cylinders    : hex 309  	dec 777
tracks per cylinder    : hex 10  	dec 16
blocks per track       : hex 80  	dec 128
blocksize              : hex 200  	dec 512
$ sudo dasdview -i /dev/dasdb

--- general DASD information --------------------------------------------------
device node            : /dev/dasdb
busid                  : 0.0.0300
type                   : ECKD
device type            : hex 3390  	dec 13200

--- DASD geometry -------------------------------------------------------------
number of cylinders    : hex 2720  	dec 10016
tracks per cylinder    : hex f  	dec 15
blocks per track       : hex c  	dec 12
blocksize              : hex 1000  	dec 4096