And now something completely different: need a slow share

[BitSprocket]

Hello all! I'll wager this has never come up: I need a very slow smb share. Seriously? Yes.

I have a major client (DoD) that I write software for and their network is incredibly slow due to encryption at rest, application firewalls, malware scanning on access etc. As a result, my software runs incredibly slowly. What I want to do is replicate their performance so that I can figure out how to optimize my app such that people don't get the impression that it has frozen and terminate it - killing my databases. Before you ask, no - I cannot use anything but a flat file database as there is no such available resource on their networks so I'm stuck with a Microsoft Access (I know) back end. Can you help me create a share that performs terribly (but not broken) so that I can simulate their environment?

I figured this would be good for a few chuckles, but I am serious - I do need to slow my app WAY down so I can implement caching or some other performance enhancements to mitigate the network constraint. Any advice would be greatly appreciated!

 

[m0nkey_]

You might be able to leverage pf to do this if using physical hardware.

Or a better idea, things like VMware Workstation and VirtualBox have settings to allow you to experiment with slow connections and even packet loss. You could put FN into one of these and limit the traffic.

 

[BitSprocket]

Thanks M0nkey_

I wish I wasn't such a noob because your ideas sound very interesting. By pf to you mean a packet filter? I don't think I remember seeing anything like that in 11.1. As for the virtual machines, I am very familiar with vBox but again, I'm not sure I've ever seen a network throttle anywhere but I will give it a close look. And I have no idea what FN is :) . Thank you for your help - very much appreciated.

Also, for a little more clarity, I am using a Dell R510 with a PERC H200 in IT mode with 12x2TB drives in RaidZ2. I don't want the whole server running slowly (unless I can just flip a switch when I need poor performance) just ideally a single slow share.

Thoughts?

 

[Chris Moore]

I was thinking that you might be able to find a 10/100 switch and put that between the server and the workstation when you want to slow down the network. Take it out for normal speed. Should be a simple way to get poor performance and you probably could pick it up from eBay for $20 or so.

Sent from my SAMSUNG-SGH-I537 using Tapatalk

 

[BitSprocket]

Hi Chris,

I do have a 10/100 hub that I could use but I still think that will be too fast. I need this to be aggravatingly slow. I was even thinking of putting in an old 5400rpm laptop spinner to see if that would perform slowly but all my drive bays are full. Are there no tunables I could use to throttle a particular share? I know this all flies in the face of having a freenas system in the first place so if I need to spin up a separate server with a small share I could do that. I was just hoping that with all the threads here about poor performance someone might know of a way (or series of ways that I could implement) that would bring a single share to its knees. Even if I have to slow the whole array down (it's in my lab so it wouldn't affect anybody but my wife) while working on the software - that could be an option.

 

[BitSprocket]

Along the lines of your suggestion Chris, I am connecting to the box via a Juniper 1Gbps managed switch - I wonder if I could change a configuration on that one port that would bring the bandwidth down to say 5Mbps while I'm working and then bring it back up when I'm done... That might be an easier route rather than trying to bring the freenas box to a crawl. What do you think?

 

[Chris Moore]

It's worth a try.
I spend most of my time trying to make it work faster, so I have to confess that I am at a loss for ideas where making it slow is the goal.
I will look at the options available and see what I can find.

Sent from my SAMSUNG-SGH-I537 using Tapatalk

 

[BitSprocket]

Thanks all for the assist. I used iperf to test the network speed between the FreeNAS box I'm decommissioning and the replacement and was able to get about 960Mbps which I find very acceptable on a 1Gbps link. I then set the port on the Juniper router that is in use by the new box to 10Mbps/half duplex and re-ran the test and it dropped the speed to about 6Mbps. I think I'm on the right track. I'm going to test my software and see if it performs poorly (how often does one root for poor performance - lol) and report my results.

 

[BitSprocket]

Well, I'm on the right track but I need it even slower. I think the next step is to slow the network down even further but that will take some figuring out because the Juniper web control interface only goes down to 10Mbs. I need it even slower. Again, thanks for the assist!

 

[garm]

If you have pfSense you can set up a limiter to shape the bandwidth what ever way you would like. Just set up a vlan dedicated to slow traffic and route all traffic through the firewall (no switches in between).

 

[BitSprocket]

Well, I got the network down to about 200Kbps with traffic shaping on the switch but it's still too fast. I wonder if sticking a thumb drive in a usb slot and making it a share might help...

 

[BitSprocket]

Sorry garm, didn't see your post. Will pfSense let me shape it slower than 256Kbps? I don't have it running (never used it before) but I was thinking of installing it for my network edge anyway...

 

[garm]

The Limiters feature sets up dummynet(4)pipes. Dummynet was designed to simulate any kind of network connection. Various types of connections can be simulated such as Dialup, T1, a T1 run through a microwave oven, or a satellite connection to the Moon.

(my emphasis)
https://www.netgate.com/docs/pfsense/trafficshaper/limiters.html

I think they got you covered ;)

 

[BitSprocket]

Most excellent! Thanks again all!