>>> Shane Presley <[EMAIL PROTECTED]> 4/7/2005 9:46:17 AM >>> When we fire off our backups at midnight, we see lots of ports max out (95% utilization or about 11MB/s). They all are sending data to our uplink port (media server). But what's odd is the gigabit uplink port only shows 10% utilization (11MB/s).
Since we have multiple ports sending data at exactly the same time (midnight) and MRTG accurately reflects this, we expected to see an aggregate bandwidth to the uplink of about 40MB/s. If you look at the graphs and add up the various servers sending 11MB/s in, how can the uplink also only be doing 11MB/s out.<<< Umm, because it's a switch and not a hub? Remember the way switching technology operates. It tries to preserve the bandwidth and keep each connection "private" and not share it like a hub would. Therefore you do not "add up" the total data going in, because the switch, if at all possible, is going to try to preserve the speed for each connection. So in your case: Server 1 - Media Server = 11Mbps Server 2 - Media Server = 11Mbps Etc. Uplink shows 11Mbps and if you had a setup like this: Server 1 - Media Server = 100Mbps Server 2 - Media Server = 11Mbps Uplink shows: 100Mbps Now in your case if you had 4 servers connected via a hub,and the hub was connected to a switch port and then had that sending data to the uplink port you get 4X11mbps to the uplink. The actual numbers on the gigabit port going out may fluctuate a litte bit but should remain close to the largest amount of data it is receiving. Essentially your servers are not even coming close to taxing your gigabit port, it is easily handling what you are throwing at it. (this is a good thing :P) There may be another way to make MRTG realize what you want which from what you are saying you want the TOTAL amount of data going across it, I myself am not sure, perhaps some others on this list have some suggestions? (Try Jan's he seems to know what he is talking about. :P ) HTH Steve Woodin A+,CNA6 [EMAIL PROTECTED] -- Unsubscribe mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/mrtg FAQ http://faq.mrtg.org Homepage http://www.mrtg.org WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
