Moving up from an RB750UP - some questions

VanceG · July 10, 2020, 7:38pm

I have an RB750UP (original version) that has been taking care of a small remote network for years. It is running a hotspot to regulate user access. It’s set up just as I want and has been running well.

Recently (after many years) I finally got a decent backhaul and usage has increased dramatically (more simultaneous users and more time spent online).

Lately, I have had some weird behaviors and one outright reboot due to low memory (something less than 5MB). The low memory reboot was logged in the echo section of the log so I could see it when it came back up. Probably due to the increase in usage. I know the hotspot is a memory hog. Not much I can do about that.

So, looks like it might be time to move up the Routerboard chain to something with a little more horsepower and RAM. Have more or less decided on the hEx POE.

I have some questions about this move:

The hEx POE actually has less disk than the 750 (16M vs. 64). Right now, the disk usage on the 750 is 16.67M out of 64.

Given that I intend to have the same config on the hEx as I do on the 750, is this going to be a problem? Or is the architecture of the hEx POE such that it doesn’t need so much disk? Maybe plug in a USB stick to get more storage?

I would like to migrate the current config from the 750 to the hEx POE using EXPORT. I know from past instances of doing this (OK, trial and error), that there is a specific order to how you restore pieces of the script (/ip addresses before /ip hotspot, for example). Is there any guidance on the proper order to do this? The couple times I have applied a complete export script all in one go things got weird and I had to go in and fix some settings.
Will there be any syntax differences between these two or is script text basically hardware independent? Should any MAC addresses that refer to the router itself need to be changed? Will I be able to import sections of the script (in the proper order as previously discussed) as-is? I hope this is so as it’ll be no fun at all to rebuild the new hEx from scratch (especially the hotspot), but if that’s what it takes I will do it.

In the meantime, do any of you have any advice on how to free up RAM on the 750? I won’t be able to get to the site for another month and need to keep it up and running until then. I know the hotspot is a memory hog. Not much I can do about that. I have already removed all unused firewall rules, etc. that I can find.

Be aware that this device is a 8 hour drive and 1.5 mile hike to a solar powered site, so I need to be very, very careful that anything I do remotely doesn’t kill it.

I appreciate any advice you can give.

vasilaos · July 16, 2020, 12:20am

I would suggest RB4011iGS+RM for long term solution. Compared to hex poe i think hex S is a better option but have to consider that will have 5MB of free space with clear configuration out of the box. Definitively space is an issue on these devices. You could load images and other large files or scripts from an external server in order to save space as workaround. You could debug a little more also why ram memory is filled up. When rebooted is it near full or gets filled with time? If its low but gets filled fast with time it could be due to some extra feature like API. Import from from another router configuration i have done always step by step from the export script maybe also cleaning or correcting something in the process. Almost always failed with all in one import. The correct order is that of the export script but with the step by step method you can reverse back a step and correct in case of an error. Syntax is RouterOS version dependent. mac adresses are not anymore exported by default.

VanceG · July 22, 2020, 5:31pm

Thanks for the input.

It is good to know that the order in which things are exported is also the order in which they should be restored. One could assume that was the case but I wasn’t able to confirm that.

I already know that restoring all at once tends to not work and won’t be doing that.

Memory tends to be pretty consistent after ramping up a little after a reboot (things getting mapped in, etc. I suppose). I have squeezed about 1M additional by eliminating some things I am no longer needing. Will keep an eye on the situation until the upgrade happens. I can always schedule a reboot in the middle of the night every couple days if necessary to keep usage as low as possible.