Source: https://hanheld.wordpress.com/2014/09/15/saving-inventory-with-save-iar/
Backing up stuff to an .iar file
The basic steps to create an IAR file are to start up a simulator (a copy of opensim.exe) and connect to metro. the region doesn’t matter -it can be an empty sim, it doesn’t matter. what matters is gettting the console. (pick an empty spot on the map and put those in as the co ordinates when opensim asks)
If you just want to back up a few things (eg stuff you’ve grabbed off of the hypergrid), make a folder in your inventory and move the boxes or folders into it….
For example, make a folder name “hg_dl” (hypergrid downloads)
Start up the simulator as I said and go over to the console.
In the console you’d type (assuming this is in windows):
save iar Han Held hg_dl MYPASSWORD c:\downloads.iar
That’s it, in a nutshell. That will put your IAR file into the root (bottom) of your “c:” drive, and from there you can copy it where-ever you want. An easier alternative might be to use the “bin” folder of your simulator software, in which case you’d simply type:
save iar Han Held hg_dl MYPASSWORD downloads.iar
and then move it somewhere else (eg. “my documents”) with Windows explorer.
Saving EVERYTHING to an .iar file
You’ll notice that I didn’t explain how to save one’s entire inventory, but only a single folder. To save your entire inventory to an iar file called “inventory.iar” you would type:
save iar Han Held / MYPASSWORD inventory.iar
Restoring an .iar file
to load that iar, you do something similar:
load iar Han Held / MYPASSWORD c:\downloads.iar
hopefully this helps. For more details, see the opensimulator wiki page on “inventory archives”: