what is the true free space amount calculation on the dmx-3?

symdev list -noport will list devices that are already created and not mapped ( be careful to check if you are using clone devices that could be in use for some other purposes, even though they are not mapped. For example we use clones for a weekly copy over SRDF to remote site, these clones are not mapped to FAs ..but we did put them in a device group)

symdisk commands give you raw space, for example look at this group

Disk Group Name              : DISK_GROUP_001
Technology                   : N/A
Speed (RPM)                  : 10000

                                                         Capacity(MB)
Ident  Symb Int TID Vendor     Type       Hypr   Total       Free      Actual
------ ---- --- --- ---------- ---------- ---- ---------- ---------- ----------
DF-1A  01A    D  23 SEAGATE    T300R10      37     286102     156917     286102
DF-2A  02A    C  23 SEAGATE    T300R10      38     286102     172831     286102
DF-15A 15A    D  23 SEAGATE    T300R10      37     286102     156917     286102
DF-16A 16A    C  23 SEAGATE    T300R10      38     286102     172831     286102
DF-2B  02B    D  23 SEAGATE    T300R10      37     286102     175585     286102
DF-16B 16B    D  23 SEAGATE    T300R10      37     286102     175585     286102
DF-1C  01C    D  23 SEAGATE    T300R10      37     286102     151433     286102
DF-2C  02C    C  23 SEAGATE    T300R10      38     286102     172831     286102
DF-15C 15C    D  23 SEAGATE    T300R10      37     286102     151433     286102
DF-16C 16C    C  23 SEAGATE    T300R10      38     286102     172831     286102
DF-1D  01D    C  23 SEAGATE    T300R10      37     286102     181069     286102
DF-1D  01D    D  22 SEAGATE    T300R10      38     286102     172831     286102
DF-15D 15D    C  23 SEAGATE    T300R10      37     286102     181069     286102
DF-15D 15D    D  22 SEAGATE    T300R10      38     286102     172831     286102
                                               ---------- ---------- ----------
Total                                             4005432    2367000    4005432

so it says that i have ~2.3 TB free but be careful because you may not be able to provisioned all that due to gaps of free space, other protection rules. Best thing to do is to create a symconfigure script that will create devices of your normal size, run this script in preview mode and see if it succeed. Increase the number of devices each time and eventually it will say it can't create devices because it does not satisfy raid requirements ..or something of that nature.