Hey, I had today a very difficult task (ironic): to modify quota on a destination time machine.
So, as usual, without too much blabbing, below is an example of how I have modified quota for TM destination.
fmbp16:~ zub$ tmutil destinationinfo ==================================================== Name : mbp16TM Kind : Network URL : smb://zub@MINIVM._smb._tcp.local./mbp16TM ID : 1 > ================================================== Name : TM Kind : Network URL : smb://zub@myarm._smb._tcp.local./TM ID : 2 Quota : 2,5 TB fmbp16:~ zub$ tmutil setquota 2 3000 tmutil: setquota requires root privileges. fmbp16:~ zub$ sudo tmutil setquota 2 3000 Password: fmbp16:~ zub$ tmutil destinationinfo ==================================================== Name : mbp16TM Kind : Network URL : smb://zub@MINIVM._smb._tcp.local./mbp16TM ID : 1 > ================================================== Name : TM Kind : Network URL : smb://zub@myarm._smb._tcp.local./TM ID : 2 Quota : 3 TB fmbp16:~ zub$