By default, LUN 0 is assigned to the ME4 Series system. This assignment is completed as soon as the host has visibility to the ME4 Series system (for example, when FC zones are created for the host and ME4 Series system, or when the host iSCSI initiator logs in to ME4 Series iSCSI ports). Therefore, the very first volume mapped to the Linux host starts with LUN ID 1.
# lsscsi -is
[0:0:0:0] cd/dvd QEMU QEMU DVD-ROM 0.10 /dev/sr0 - -
[6:0:0:0] enclosu DellEMC ME4 G275 - - -
[6:0:0:1] disk DellEMC ME4 G275 /dev/sdl 3600c0ff0003c589fe452605b01000000 99.9GB
[7:0:0:0] enclosu DellEMC ME4 G275 - - -
[7:0:0:1] disk DellEMC ME4 G275 /dev/sdn 3600c0ff0003c589fe452605b01000000 99.9GB
[8:0:0:0] enclosu DellEMC ME4 G275 - - -
[8:0:0:1] disk DellEMC ME4 G275 /dev/sdj 3600c0ff0003c589fe452605b01000000 99.9GB
[9:0:0:0] enclosu DellEMC ME4 G275 - - -
[9:0:0:1] disk DellEMC ME4 G275 /dev/sdk 3600c0ff0003c589fe452605b01000000 99.9GB
[10:0:0:0] enclosu DellEMC ME4 G275 - - -
[10:0:0:1] disk DellEMC ME4 G275 /dev/sdm 3600c0ff0003c589fe452605b01000000 99.9GB
[11:0:0:0] enclosu DellEMC ME4 G275 - - -
[11:0:0:1] disk DellEMC ME4 G275 /dev/sdi 3600c0ff0003c589fe452605b01000000 99.9GB
[12:0:0:0] enclosu DellEMC ME4 G275 - - -
[12:0:0:1] disk DellEMC ME4 G275 /dev/sdh 3600c0ff0003c589fe452605b01000000 99.9GB
[13:0:0:0] enclosu DellEMC ME4 G275 - - -
[13:0:0:1] disk DellEMC ME4 G275 /dev/sdg 3600c0ff0003c589fe452605b01000000 99.9GB
To reclaim LUN 0 for a regular volume, manually unmap and remap the volume in ME Storage Manager. In ME Storage Manager under the Volumes topic, right-click the desired volume and click Map Volumes. On the Map volume interface, override the LUN ID.
On the Linux host, perform a force rescan on all SCSI buses. This removes the enclosure entries and the volume is assigned to LUN 0.
# rescan-scsi-bus.sh --forcerescan
# lsscsi -is
[0:0:0:0] cd/dvd QEMU QEMU DVD-ROM 0.10 /dev/sr0 - -
[6:0:0:0] disk DellEMC ME4 G275 /dev/sdg 3600c0ff0003c589fe452605b01000000 99.9GB
[7:0:0:0] disk DellEMC ME4 G275 /dev/sdh 3600c0ff0003c589fe452605b01000000 99.9GB
[8:0:0:0] disk DellEMC ME4 G275 /dev/sdi 3600c0ff0003c589fe452605b01000000 99.9GB
[9:0:0:0] disk DellEMC ME4 G275 /dev/sdj 3600c0ff0003c589fe452605b01000000 99.9GB
[10:0:0:0] disk DellEMC ME4 G275 /dev/sdk 3600c0ff0003c589fe452605b01000000 99.9GB
[11:0:0:0] disk DellEMC ME4 G275 /dev/sdl 3600c0ff0003c589fe452605b01000000 99.9GB
[12:0:0:0] disk DellEMC ME4 G275 /dev/sdm 3600c0ff0003c589fe452605b01000000 99.9GB
[13:0:0:0] disk DellEMC ME4 G275 /dev/sdn 3600c0ff0003c589fe452605b01000000 99.9GB
Note: Only use the --forcerescan option for removing the enclosure entry and reclaiming LUN 0.