That's what I get for posting before I'm totally awake. This is what I get when I run the command on my group:

BackupTarget> show member Name Status Version Disks Capacity FreeSpace Connections ---------- ------- ---------- ----- ---------- ---------- ----------- 16TB online V7.0.7 (R3 16 11.34TB 6.72TB 2 97085) syr-8TB online V7.1.2 (R4 16 5.66TB 3.69TB 3 02088) 4TB online V7.0.7 (R3 16 2.83TB 1.84TB 2 97085) BackupTarget>

I think the command is showing the free space on the volumes after creation, not before since I think I have mine fully provisioned.

Just type:
show
and it will scroll through all the things under the show command and you should be able to figure out the size of your member. This is just the first of like 4 pages:

BackupTarget> show ______________________________ Group Information ______________________________ Name: BackupTarget Group-Ipaddress: 192.168.100.21 DateAndTime: Thu Apr 20 03:32:04 2017 TimeZone: America/New_York TotalVolumes: 3 VolumesOnline: 3 VolumesInUse: 3 TotalSnapshots: 0 SnapshotsOnline: 0 SnapshotsInUse: 0 TotalMembers: 3 MembersOnline: 3 MembersInUse: 3 TotalCapacity: 19.83TB VolumeReserve: 7.58TB VolumeReportedSpace: 7.58TB SnapReservedSpace: 3GB SnapReservedSpaceInUse: 0MB ReplicationReservedSpace: 0MB FailbackReservedSpace: 0MB DelegatedSpace: 0MB DelegatedSpaceInUse: 0MB FreeSpace: 12.24TB TotalDisks: 48 OnlineDisks: 45 SpareDisks: 3 OfflineDisks: 0 FailedDisks: 0 Collections: 0 Snapcols: 0 CustomSnapcols: 0 ThinProvFreeSpace: 122.49TB TotalSpaceBorrowing: 0MB Connections: 7 _______________________________________________________________________________

Interesting. Though it doesn't indicate that one could limit - only set a ringer volume. I'll have to try.

Thanks. I found other Mitel docs just not that one.