Log shipping retention question

Question

One of the secondary's is failing log shipping restore due to insufficient drive space. This might not be looked at by IT for several days. Can log shipping primary server purge transaction log backup before secondary has a chance to restore in this scenario? Or does Log shipping primary just hold onto transaction log backups until all secondary's have restored it?

Answer 1

The primary server must retain all transactions until the secondary restores them and acknowledges to the primary.

You must constantly monitor both the primary and secondary servers to avoid this situation.