running snort as packet logger and nids simultaneously

[Metal Gear <finattack () gmail com>]

hi all,
is this possbile to run snort as both packer logger and nids simultaneously 
as i m trying to run snort with the following command but i m not getting 
the packet logs in 'snortlogs' folder

/usr/local/bin/snort -u snort -g snort -l /var/log/snortlogs -b -c 
/usr/local/etc/snort.conf -D

but when i run as 
/usr/local/bin/snort -u snort -g snort -l /var/log/snortlogs -b -D
it can now log packets in the respected folder,

Thanks