Improvements for small business network?
Solution 1:
Are there any easy ways we can get performance increases?
You need to employ a systematic process of identifying bottlenecks and eliminating them. You can shovel money into new gear, services, etc, but if you're not being methodical about it there's really no point. I'll make some specific recommendations at the end of my answer for some things you should look at.
Would it make sense to get a switch with a fiber port and then put in a fiber NIC on the server?
Nope. Your fiber-based Ethernet media choices are gigabit and 10 gigabit. Gigabit fiber and gigabit copper are the same speed, so there's no "win" to using fiber for gigabit speed (though, as @ChrisS says, fiber does excel in some specific use cases). You don't have a server in your office that can even begin to saturate 10 gigabit fiber, so there's no "win" with 10 gigabit either.
I haven't even Google'd how to log into the Dell switch, so I'm assuming it's unmanaged. I was going to visit the switch for a webserver so I checked the DHCP server (on firewall box) and the switch doesn't show up among the clients. I've only scratched the surface of reading up on all that: should the switch and RAID server be using large packets or something?
The PowerConnect 2716 is a low-end "web managed" switch when its set up in "Managed" mode (which, by default, it isn't, but it sounds like you've figured out you can enable web management). You can get a manual from Dell for that switch that will explain the management functionality. They aren't great performers. I've got a couple of them in little "backwater" places and my experience has been that they won't even do wire-speed gigabit switching.
When you say "large packets" I believe you're referring to jumbo frames. You have no reason to use jumbo frames. Generally you'll only see jumbo frames in use in very specialized, isolated networks-- like between iSCSI targets and initiators (SANs and the servers that "connect" to them). You're not going to see any marked improvement in general file/print sharing performance on your LAN using jumbo frames. You'd likely have headaches and performance problems, actually, because all the devices would need to be configured for jumbo frame support-- and I would suspect that you have at least one device that doesn't have support (just based on the wide variety of gear you have).
Here are some things I'd look at doing if I wanted to isolate bottlenecks:
Enable web management on the PowerConnect 2716 switch so that you can see error and traffic counters. This switch doesn't have SNMP-based management so you're not going to get any fancy traffic graphing, but you'll at least be able to see if you're having errors.
Benchmark the server performance w/ a single client computer connected directly to the server's NIC (for which you should be able to use a regular straight-through patch cable, assuming the client computer you're using has a gigabit NIC). That will give you a feeling for the server's maximum possible I/O throughput with a real file sharing workload. (If I had to hazard a guess I'd bet that the server's I/O to/from the disks is your biggest bottleneck.)
Use a tool like iperf (ttcp, etc) to get a feeling for the network bandwidth available between various places in the network.
The best single thing you can change, from a reliability perspective, is to eliminate all the little Ethernet switches and home-run all the cabling back to a single core switch. In a network as small as the one you've diagrammed there's no reason to have more than a single Ethernet switch (assuming all the nodes are within 100 meters of a single point).
Solution 2:
Are there any easy ways we can get performance increases?
Without having any specific pain points you could throw money at everything and get better all around performance, but it'd be little more than a waste of money.
Would it make sense to get a switch with a fiber port and then put in a fiber NIC on the server?
Nope. Fiber is excellent for three things:
- Long runs, ie over 300 ft
- Dielectric isolation, usually desirably in electrically "noisy" environements and between environments that don't share a common ground (usually between buildings in a campus).
- Leading-edge connectivity solutions. 10GbE Fiber appeared long before 10Gbase-T. There's 40GbE and 100GbE Fiber out already, nothing available for twisted pair copper (as of 2013).
Gigabit reigns king of small and medium networks. 10GbE is just gaining real popularity in core networks, but not at the access level. If you're bottlenecked at some point, aggregating links is likely plenty enough to solve the issue and much cheaper than trying to wedge 10GbE into your setup.
should the switch and RAID server be using large packets or something?
Nope. Jumbo packets are great for storage area networks, high performance computing, and their like, but have little use in small or access level networking. With your relatively simple, small network I'd leave the MTU at 1500 all around. Changing to Jumbo can introduce problems if not done carefully.
saves of 40M+ take 10 or so seconds.
40MB/10s => 32Mbps, that's pretty weak if you're running 1000Mb Ethernet with a reasonably modern server. You likely have a bottleneck somewhere, but without much more information I couldn't say where or start to offer a solution.
Managed switches are good for a variety of things, most commonly setting up VLANs, security (possibly 802.1x), reviewing bottlenecks and statistics, link aggregation, and a variety of other advanced functionality. However, I'm not sure your setup needs any of that, and managed switches tend to cost a pretty penny. (On that note I always recommend "budget mindful" businesses consider buying used ProCurve gear. It comes with a transferable lifetime warranty and you can find a large selection on eBay. And there are official resellers on there too, just add "ReNew" to your search).
Solution 3:
I personally would benchmark the speed you're getting from the TU2-ETG, this will probably not be a bottleneck to your service provider, but since you're saying you get faster speeds after removing the 100mbps switch this might be your next part.
The TU2-ETG claims to have a Gigabit link, but the other side of this link is USB 2.0, which has a maximum signaling rate of 480 Mbit/s (effective throughput up to 35 MB/s or 280 Mbit/s), I for one have never been able to get speeds higher then 20MBps over a usb connection.
I could not find any real benchmarks from this device, so try to do a benchmark or two and see what this gives you. This is probably only relevant if your internet uplink is faster then 100mpbs, but then again, I see your provider offers 150mbps packages.
So be aware this is definitely not a gigabit network card.