So another question...
is it possible to run the oclvanitygen and stop and safe it and later continue?
Or are -f -o -s only for the actual found addresses?
It depends a bit on what you would consider a 'save' state.
-f --> input file
The input file of the matches you want to find, if the -k is not used a found match would be scratched of the list.
Restarting would put it back on the list.
-o --> output file
output file, no change here with start/restart. all found matches will be appendend.
-s --> seed file for randomness.
This is a tricky one. The brute force search requires a high entropy source for the EC-Points generation to be truly random.
If you have a system that has a more psuedo random entropy source; i.e. a possiblity to repeat the randomness in a set time,
and you might end up generating the same sequence of addresses all the time.
Using a seed file to bring in more randomess could help here.
Most OS-systems use a combination of randomness like CPU temp, time, HDD temp, HDD head locations etc to generate something true random.
I don't know if this the same case when a GPU is used.
So in a restart, if you are using -s, I would advice to use a different file each time you restart.