dedupe no preferred_iscsi_port_id active_iscsi_port_id replacement_date over_provisioned yes supports_unmap yes provisioning_group_id 0 physical_capacity 85.87TB physical_free_capacity 78.72TB write_protected no allocated_capacity 155.06TB effective_used_capacity 16.58TB. IBM_FlashSystem:FLASHPFE95:superuser> lsMDisk 1 id 1 name flash9h01_itsosvccl1_0 status online mode managed MDisk_grp_id 1 MDisk_grp_name Pool1 capacity 51.6TB quorum_index  block_size 512 controller_name itsoflash9h01 ctrl_type 6 ctrl_WWNN 500507605E852080 controller_id 1 path_count 16 max_path_count 16 ctrl_LUN_# 0000000000000000 UID 6005076441b53004400000000000000100000000000000000000000000000000 preferred_WWPN  active_WWPN many NOTE: lines removed for brevity Example 10-4 on page 365 shows that for MDisk 1, the external FlashSystem FS900 has  eight ports zoned to IBM FlashSystem 9100, and IBM FlashSystem 9100 has two nodes,  so 8 x 2= 16. GLYPH<SM590000> lsvdisk GLYPH<SM590000> lsfabric Check that all volumes are online (not degraded or offline). If the volumes are degraded,  are there stopped FlashCopy jobs? Restart any stopped FlashCopy jobs or seek IBM  FlashSystem 9100 support guidance. Use this command with the various options, such as  -controller  controllerid . Also,  check different parts of the IBM FlashSystem 9100 configuration to ensure that multiple  paths are available from each IBM FlashSystem 9100 node port to an attached host or  controller. Confirm that all IBM FlashSystem 9100 node port WWPNs are also connected  to any of the optional external back-end storage consistently. 366  IBM FlashSystem 9200 and 9100 Best Practices and Performance Guidelines