2016-06-15 22:59 GMT+02:00 Nick Fisk <n...@fisk.me.uk>: > Possibly, but by how much? 20GB of bandwidth is a lot to feed 12x7.2k disks, > particularly if they start doing any sort of non-sequential IO.
Assuming 100MB/s for each SATA disk, 12 disks are 1200MB/s = 9600mbit/s Why are you talking about 20Gb/s ? By using VLANs on the same port for both public and cluster traffic, i'll have 10Gb/s to share, but all disks can saturate the whole nic (9600mbit/s on a 10000mbit/s network) I can't aggregate 2 ports, or I have to buy stackable switches with support for LAG across both switches, much more expansive. And obviously I can't use only one switch. Network must be fault tollerance. > I think you want to try and keep it simple as possible and make the right > decision 1st time round. Buy a TOR switch that will accommodate the number of > servers you wish to put in your rack and you should never have a need to > change it. > > I think there are issues when one of networks is down and not the other, so > stick to keeping each server terminating into the same switch for all its > connections, otherwise you are just inviting trouble to happen. This is not good. a network could fail. In a HA cluster, network failure must be taken in consideration. What I would like to do is to unplug cable from switch 1 and plug to switch 2. a couple of seconds max. (obviously switch2 will be temporary connected to switch1) _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com