cpio block size on HP-UX 11iv1.

[Powerless]

I need to get a much larger block size than the standard 5120 bytes when writting to tape using cpio. Any pointers please.

[Dennis Handly]

I don't see anything other than -B for 5120.
You can pipe the output to dd(1) to increase the blockize:
cpio -o -B | dd ibs=5120 obs=30720 > /dev/...

Or you could just give up on cpio and go to pax which supports more block sizes:
pax -w -f /dev/... -x cpio -b 32256

[Powerless]

Thanks for the suggestions, will pass these on to the user and see how we get on. For historic reasons they want to stay with cpio!

[Dennis Handly]

>For historic reasons they want to stay with cpio!

Why? cpio and tar can be replaced by pax(1). pax does both and the options have been rationalized.
Of course with the larger blocksize, you would need pax to read your tape.

[Dennis Handly]

In case it isn't obvious, you should make sure you are able to read the files you put on the tape in this non-default manner. Whether with cpio and dd or with pax.