Yes and no. If by restore chain you're talking about a base backup and a set of log backups, no, it does not affect them. However, if you are talking about a base backup and a set of differential backups, then yes, it does completely interrupt the backup chain. Any new backup taken will cause the next differential to work from that new base, not the previous base. That's why copy only backups were introduced, to allow for a backup in the middle of the cycle that wouldn't reset the next differential.
answered Feb 19 '10 at 03:39 PM
Grant Fritchey ♦♦