2016-06-15 22:59 GMT+02:00 Nick Fisk <nick@xxxxxxxxxx>: > 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@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |