Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!husc6!m2c!jjmhome!cloud9!bob
From: bob@cloud9.UUCP (Bob Toxen)
Newsgroups: comp.unix.wizards
Subject: Re: Disk to disk copies
Message-ID: <346@cloud9.UUCP>
Date: 2 May 88 23:19:08 GMT
References: <13119@brl-adm.ARPA> <77@tarkus.UUCP>
Organization: Stratus Computer, Inc., Marlboro, MA
Lines: 16
Summary: Dd on raw disks doesn't usually copy bad blocks

In article <77@tarkus.UUCP>, jcs@tarkus.UUCP (John C. Sucilla) writes:
> In article <13119@brl-adm.ARPA> eichelbe@nadc.arpa (J. Eichelberger) writes:
> >(Paraphrased) Will a dd to copy disk devices directly (blocked or raw)
> >copy bad block information (which you don't want to copy)?

Not in most installations.  That should be handled at a lower level.
If you have a utility to read bad blocks, see if you have any.  Then
do a dd to /dev/null and see if you get any read errors on the console.

This is also a handy way to see if you've developed any new bad blocks.
A dd of raw disks with a very large blocking factor (or of disk to/from
tape) is a fast way of cpying.
-- 

Bob Toxen	{ucbvax!ihnp4,harvard,cloud9!es}!anvil!cavu!bob
Stratus Computer, Marlboro, MA
Pilot to Copilot: What's a mountain goat doing way up here in a cloud bank?