USB raid or rsync or mirror

[wah00kid]

In looking around for solutions for which usb to use for the swap and such I wondered about my server where my boot device is basically a mirrored zfs pool with two small msata drives. Now I know that my server has a lot more horsepower to do the software raid.

I am still wondering about any solution to create a backup to the usb swap device. I have a rt-ac3100 so I have a usb2 and a usb3 port... Can I set up a mirror somehow or set up some sort of overnight scheduled rsync that would allow easy swap in case of a failure?

 

[ColinTaylor]

There's no point backing up swap files/partitions because they only contain transient data. If they become corrupted just recreate them.

 

[wah00kid]

okay i got that.. how about this:

i have an rt-ac3100 that is all set up with all the merlin goodies running.

can I clone that to another rt-ac3100?

i.e. is there something on the system that I can backup/clone/mirror so that in the event of a blowout there is easy recovery?

 

[ColinTaylor]

Your post is confusing. You started by talking about swap devices on USB drives and now you're talking about "Merlin goodies" and two routers.

You could make a backup of the contents of one USB drive to another USB drive simply enough by using your preferred utilities, e.g. cp, rysnc, tar, etc.

You can make backups of the router's configuration settings either through the GUI of via the command line. But these backups are only useful for restoring to the same device. They should not be restored onto a different router, even if it's the same model.

 

[wah00kid]

i guess the essence of this is i thought more of the merlin add-ons/extras/goodies went on the usb.

It just takes a while to set up the swap, the entware, diversion, unbound, which is all i have now... i envision adding the qos stuff and perhaps the skynet.

Anyway since I thought more/all of that was on the usb. I was wondering about mirroring all of that, but if its just the swap file on the usb-- then you are right no need.

so if all of that stuff is on the system (nand chip - iguess?) then i guess there is no quick way of backing that up/imaging that and restoring that to a secondary rt-ac3100 should my main one go down

i guess i am just being paranoid because i recently lost my system during a power surge, i was being stupid because my UPS was in a different room because i was doing modifications to my server and so my router was unprotected--- it had been running for years with no major config changes just updating the firmware---

BUT vanilla asus is pretty easy to restore so long as you are on the same firmware and have an up to date config backup...

this merlin seems way more difficult to restore should something happen -= i guess this is the paranoia.. it probably wont happen for years -- but aside from random unlikely power surges---

there is a lot more to mess around with and potentially break -- i do this with my server all the time, i add something on - i have no idea what i am doing and I break something - this is fine because one thing i do know how to do is backup before changes and rollback after I mess something up - this is how I learned how to do my server - by teaching myself how to backup and restore first.

so i guess that is my main question how to back up a setup once it is set up..

for example lets say I want to add on skynet, well everything has been running fine for me but what if I mess something up and I want to roll back to my setup

 

[ColinTaylor]

Yes vanilla asus firmware is straight forward to restore settings, as is Merlin without any add-on scripts.

Many add-on scripts are stored on the external USB drive, as well as Entware (which a lot of scripts require). Merlin's custom configuration files/scripts as well as some add-ons (including Skynet IIRC) are not stored on USB but in the router's flash memory (/jffs). So in the end you need to backup both the jffs partition and the USB drive to be sure you have a complete set.

Settings and jffs can be backed up manually using the GUI options (I do this prior to installing a firmware update). To backup the contents of the USB drive you'd have to use the command line. I'd suggest using tar for that.

Restoring the /jffs contents from one rt-ac3100 to a replacement rt-ac3100 should be OK. The same would not be true for the newer HND routers as some of the NVRAM variables are now stored in jffs.

 

[wah00kid]

cool yes,

i think i can handle that- just barely but all of that makes sense

i see those backups in the gui and yeah i can tar the usb..

i wonder the most optimal procedure in terms of the "living" relationship between the jffs partition and the usb

this would this work:

use the gui to backup the jffs partition and settings

shutdown router

image usb

clone it

plug in cloned usb to backup router

turn on backup router

use the gui to restore settings and jffs partition

-- assuming same hardware and same merlin firmware

 

[ColinTaylor]

The above procedure would work for the jffs and USB backups.

You should not restore the "settings" file from one router to another, even if it's the same model. I know some people will say "well I did it and haven't had any problems" but it's not intended for that purpose. Merlin has stated this many times and it's even in the sticky post here.