System Administration Guide, Volume 1

Detecting the End of Media

ufsdump writes a sequence of fixed-size records. When ufsdump receives notification that a record was only partially written, it assumes that it has reached the physical end of the media. This method works for most devices. If a device is not able to notify ufsdump that only a partial record has been written, a media error occurs as ufsdump tries to write.

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