Question : Backup Transaction log

I'm trying to save some changes to a database but it tells me that
the log file is full and to back up the Transaction log,

When i try and backup the transaction log i get this error

BackupMedium::ReportIoError: write failure on backup
device 'd:\sql\data\MSSQL\BACKUP\postcodes_tlog_200308051550.TRN'.
Operating system error 112(error not found).

Anyone help im stuck ?

Answer : Backup Transaction log

You won't "damage" the data by shrinking the log, but you when you use the TRUNCATE_ONLY clause it removes the inactive part of the transaction and *doesn't* make a backup copy.

The script I run to shrink the transaction log is:

DBCC SHRINKFILE(Name>, 1)
BACKUP LOG WITH TRUNCATE_ONLY
DBCC SHRINKFILE(Name>, 1)

Example:
Database name = MyDatabase
Database log file = MyDatabase_Log

DBCC SHRINKFILE(MyDatabase_Log, 1)
BACKUP LOG MyDatabase WITH TRUNCATE_ONLY
DBCC SHRINKFILE(MyDatabase_Log, 1)

I'm not bothered about it not backing up the log so it's perfect for me.