I (probably) need to run add_drv command on sparc server to add driver for PCI card in Solaris 10, SPARC. Can it break something? Would a reboot in that case restore old system?
Did you try running "devfsadm" first?
no, all we tried so far is reconfiguration boot. but that didn't help. it seems like device is missing from /devices/pci..
is that devfsadm command safe to try?
Yes it is safe, but if reconfiguration reboot didn't help, then probably "devfsadm" won't help either. To see what exactly that command is doing run it as:
devfsadm -v
You should install the drivers before installing the PCI card. Try installing the drivers now and then do a reconfiguration reboot.
HTH