Do a "show flash" command and see if there are other files taking up space in flash that can be deleted such as crash dumps, logs, etc. Also, there may be a third original firmware that has an unusual filename that you can delete. When the TA900e ships from the factory, its firmware has a strange filename that doesn't look like the conventional ones from the Adtran download site. If so and it's older than T900E2A-R11-8-0-E.biz you can delete it and that should free up space. The second generation comes with 32 MB of flash, so both R11-8-0 and R11-9-0 should fit but it will be tight.
What does the output of "show flash" look like?
If after you've deleted all unused files to make room there still isn't enough free space, it's possible to delete the running image from flash and then upload the new one. This was a common issue with early Gen.1 hardware. Two images wouldn't fit. The box only reads the image from flash while booting, then it runs from RAM so deleting the running image from flash won't cause it to stop working but it won't be able to boot again should it crash if there is no image in flash.
Note that if the box loses power or reboots after you've deleted the running R11-8-0 image, it can't be recovered over the network. You'll have to connect to the console port and the procedure is cumbersome. So, be careful, best to have the machine on a UPS, and somewhat risky to do remotely but I've done it remotely without incident multiple times. Make sure you change the boot parameters to reflect the new primary once you've got it loaded.
(dir) 1024 coeff
(dir) 1024 Tones
16097583 bytes used, 15670467 available, 31768050 total
It looks like there just isn't enough memory to hold both.
As per Jon H:
Our firmware packages include Feature releases and Maintenance releases.
R11.4.5 is our current maintenance release and is what we would recommend for most deployments. In particular if you are doing SIP to PRI or SIP to FXS
R11.8.0 & R11.9.0 are feature releases. Feature releases depending upon what is added could
consume more memory. If there is a feature that you know you require, upgrading to a feature release would make sense, but otherwise the maintenance release is what should be loaded.
The reason for the distinction of Feature releases and Maintenance releases, is that it allows, Adtran to control our software code, while fixing issues and introducing new features. We could have one set of engineers working on a feature that is R11.8.0, and another group working on a different feature in R11.9.0. Meanwhile any bugs that uncovered, are repaired in the maintenance release. Eventually a feature release will get rolled into the maintenance release.
So the point is looking at the numerical name of the firmware image , does not ensure that you
have all of the latest fixes. The release date is more accurate.