Extended boot record
（重定向自Extended partition）
![Diagram 1. What the Starting andTotal Number of sectors values of1st entry point to and enumerate.Diagram 2. What the Starting and TotalNumber of sectors values of an EBR's2nd entry point to and enumerate.](/Images/godic/202501/12/06-02-05-embr-entry-13040.png")
![](/Images/godic/202501/12/09-02-28-ebr-entry-23040.png")
![](/Images/godic/202501/12/06-02-05-EMBR-A3040.png")
An extended boot record (EBR), or extended partition boot record (EPBR), is a descriptor for a logical partition under the common DOS disk drive partitioning system. In that system, when one (and only one) partition record entry in the master boot record (MBR) is designated an extended partition, then that partition can be subdivided into a number of logical partitions. The actual structure of that extended partition is described by one or more EBRs, which are located inside the extended partition. The first (and sometimes only) EBR will always be located on the very first sector of the extended partition.