We use log shipping in our 2008 R2 databases. On one of our large heavily used databases, transaction log backups are run every two minutes. Each TL backup is around 50MB in size when the primary server is used heavily. We use TDE on the database and backup compression.
The files are transferred quickly, but the restore job takes a long time during peak times. For example when heavy load is placed on the server, I've noticed the restore job to fall behind by nearly 24 hours. The transaction logs are safely copied to the remote server, so in the event of primary failure, we would be able to restore back, up to the last copied file, but the restore time objective could potentially be 24 hours whilst we wait for the restores to complete.
Can anyone help with why the restores are taking so long? What factors do I need to consider? The DR server is slightly different spec to production so I am expecting it to be hardware related, but would be good to get other ideas.