How to install additional packages in freenas 0.8

Actually, freenas 0.8 fell into the hands of a problem to install iperf, with simple googling I find the command pkg_add -r iperf , where -r means to install iperf from the repository, but in the frinas root is mounted only for reading:
freenas2 # mount
/ dev / ufs / FreeNASs1a on / (ufs, local, soft-updates)
devfs on / dev (devfs, local, multilabel)
/ dev / md0 on / etc (ufs, local)
/ dev / md1 on / mnt (ufs, local)
/ dev / md2 on / var (ufs, local)
/ dev / ufs / FreeNASs4 on / data (ufs, local, soft-updates)
data on / mnt / data (zfs, local)

The existing solutions I found are based on all sorts of chroot and unionfs and were quite stressful.

Actually treated by the team:
mount -o rw / dev / ufs / FreeNASs1a /
')
And voila any software you can put pkg_add -r.