Appending a CPIO to an existing archive

Shell Programming and Scripting
1

I created a CPIO archive I wanted to add addition data to it but am having issues:

-rw-r--r-- 1 test test 629295104 2011-10-28 12:41 /home/test/Downloads/test.cpio

I tried:

sudo find /tmp -depth | cpio -oAO /home/test/Downloads/test.cpio
cpio: premature end of file

and

sudo find /tmp -depth | cpio -oAF /home/test/Downloads/test.cpio
cpio: premature end of file

Any ideas ??

2

Not exactly what I want but inspirational and untested

'cat cpio1 cpio2 > | gzip > cpio_all'

Will test a return the results