combinedeltarpm man page
combindeltarpm — combine multiple deltarpms to a single one
combinedeltarpm [-v] [-V version] [-z compression] [-S signaturerpm] olddeltarpms... newdeltarpm
combinedeltarpm creates a new deltarpm from multiple old ones. Applying the rsulting deltarpm has the same effect as applying each of the old ones in the specified order. Use the -v option to make combinedeltarpm more verbose about its work.
combinedeltarpm normally produces a V3 format deltarpm, use the -V option to specify a different version if desired. The -z option can be used to specify a different compression method, the default is to use the same compression method as used in the last of the old deltarpms.
If you want to use a different header signature you can also specify a rpm with the -S option which will be used as signature reference. This feature can be used to if a deltarpm was made against an unsigned rpm which later got signed.
The implementation of combinedeltarpm currently unpacks the add-blocks of the deltarpms in memory, thus it needs about twice the uncompressed payload size of the target rpm.
Michael Schroeder <firstname.lastname@example.org>