Thanks for the advice Peter, > You could get a cisco switch that supports cut through instead of > store-and-forward, for lower latency. Interesting option, but those cost ~?10K and are out of our price range unfortunately. The "cut through" switching technology is also available in Dell's new Force 10 range I believe. > Other than that, compare the port to port forwarding times and see if > there is a difference between the switches you are looking at (probably > not) and make your decision based on that. You're right, there isn't much of a difference between the forwarding rate of the 5548 and the 6248, both are about 100Mpps. They also have a similar bandwidth of about 180Gbps. However the 7048 does better on both measures, with forwarding rate of 160Mpps and a bandwidth of 224Gbps. Unfortunately the 7048 costs five times as much as the 5548, and I don't know if the users would notice any difference at all. I expect some would and some wouldn't. -Dan. On 01/27/2012 01:48 PM, gluster-users-request at gluster.org wrote: > Date: Fri, 27 Jan 2012 14:16:36 +0100 > From: Peter Linder<peter.linder at fiberdirekt.se> > Subject: Re: Switch recommendations > To:gluster-users at gluster.org > Message-ID:<4F22A3B4.8000008 at fiberdirekt.se> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > You could get a cisco switch that supports cut through instead of > store-and-forward, for lower latency. > > Other than that, compare the port to port forwarding times and see if > there is a difference between the switches you are looking at (probably > not) and make your decision based on that. Consider connecting > everything to two switches, for failover in case a switch breaks? > > On 1/27/2012 2:04 PM, Dan Bretherton wrote: >> > Dear All, >> > I need to buy a bigger GigE switch for my GlusterFS cluster and I am >> > trying to decide whether or not a much more expensive one would be >> > justified. I have limited experience with networking so I don't know >> > if it would be appropriate to spend ?500, ?1500 or ?3500 for a 48-port >> > switch. Those rough costs are based on a comparison of 3 Dell >> > Powerconnect switches: the 5548 (bigger version of what we have now), >> > the 6248 and the 7048. The servers in the cluster are nothing special >> > - mostly Supermicro with SATA drives and 1GigE network adapters. I >> > can only justify spending more than ~?500 if I can be sure that users >> > would notice the difference. Some of the users' applications do lots >> > of small reads and writes, and they do run much more slowly if all the >> > servers are not connected to the same switch, as is the case now while >> > I don't have a big enough switch. Any advice or comments would be >> > much appreciated. >> > >> > Regards >> > Dan.
