[ceph-users] some ceph general questions about osd and pg

Hello togehter we want to implement a 3 nodes ceph cluster wirh nautilus. i already tested some ceph installations in our test enviroment and i have some generall questions. end of this month we will have three physical server with 256gb ram and two cpus and nerly 48 x 6tb disks. iam a little bit confused to calculate the pgs with the pgcalc on the ceph side. in the field osds what exactly meands that? the 3 physicaly osd nodes or the disks that will be used for the osds? what can you recomment us? we want later connect the ceph with rados and openstack and lvm thx in advance hfreidhof