the follow file is the actual configuraztion:

console#show running-config
!Current Configuration:
!System Description "Powerconnect 6224, 3.2.0.7, VxWorks 6.5"
!System Software Version 3.2.0.7
!Cut-through mode is configured as disabled
!
configure
vlan database
vlan 10,105
exit
stack
member 1 1
member 2 1
exit
switch 1 priority 12
switch 2 priority 1
ip address 192.168.2.21 255.255.255.0
ip default-gateway 192.168.2.99
interface vlan 10
name "vliSCSI"
exit
interface vlan 105
                 

name "Backup"
exit
username "admin" password 47219679f3d6b12d893ca00251c4fe06 level 15 encrypted
monitor session 1 mode
spanning-tree mode stp
!
interface ethernet 1/g1
spanning-tree disable
exit
!
interface ethernet 1/g2
spanning-tree disable
spanning-tree mst 0 external-cost 200000
exit
!
interface ethernet 1/g3
spanning-tree disable
mtu 9216
switchport access vlan 10
exit

I want change the spanning tree mode in  MST and don't want that the port 1/g1,1/g2,1/g3, ecc will change in "spanning-tree enable".

can you help me?

grazie!