Hmmm that's crappy. The two files are suppose to be addressed as one sequential topology, but evidently are not.
They are. SQL will use one, then the second, then the first, then the second, etc. It's a circular file, and if you have multiple files they're treated as one larger circular file. Use beginning to end, then start at the beginning.
If you have two log files, one on fast storage and one on slow, you're going to be having erratic performance, your operations will be slower when the second file is in use. I would suggest one file, sized for the database's normal usage and with autogrow so there's some spare room as necessary, plus monitoring on the backups.
Log backups failing for 5 hours aren't just a concern due to the log growing, it also means increased data loss if the production system goes down, data loss that may be outside of acceptable range.
Banking and Healthcare data doesn't care if you don't have a backup plan for backup or notification systems failures.
The bank I used to work for most certainly did. A failure of the backup system is a crisis, a failure of the notification system is a serious problem
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)SQL In The Wild
: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter
We stand on the bridge and no one may pass