A binary data file should take much less space on disk thanks to new optimizations on how values are stowed in memory. The space saved is estimated at least at 25% compared to previous format.
Structures are no longer statically allocated, meaning that the system can now register as many new devices (disks, network interfaces, etc.) as needed and you will find all of them saved in your saXX data file (provided that you have selected the corresponding activities to collect). Previous version could lead to some devices being ignored and going unnoticed if no free structures were left.
Sar (and sadf) will now be able to read a binary data file whatever its endianness is: Both big-endian and little-endian files can be read by the same sar or sadf executable.
More flexibility has been added to sar’s binary data file format. I cannot promise that the format won’t change again in the future but it should now be possible to add new metrics or activities without making the format unreadable by older sar versions (starting with version 11.7.1). Older versions will be able to read newer formats but will display only the metrics they currently know.