backup with compressed cpio files ?

Fred Fish fnf at estinc.UUCP
Sun Feb 19 17:09:53 AEST 1989


In article <9667 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>	find . -depth -print | cpio -oc | compress | dd bs=5k > /dev/rmt0

(I'm sure Doug knows this, but for the sake of completeness...)

In order to ensure that dd writes 5K records I believe you have to
specify "ibs" and "obs" to be different sizes, to force an internal
buffer copy.  Substitute "ibs=1k obs=5k" for "bs=5K".  Also note that
the last buffer may not be a full 5k, which may confuse a cpio that
reads the tape directly.

With compress, one read error and you're SOL as far as recovering the rest
of the data.  Of course, vanilla cpio is so braindead that you're SOL
anyway, so you might as well go ahead and compress it...  :-)
-- 
# Fred Fish, 1835 E. Belmont Drive, Tempe, AZ 85284,  USA
# 1-602-491-0048           asuvax!{nud,mcdphx}!estinc!fnf



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