From owner-freebsd-doc Thu Jan 25 17:17:25 1996 Return-Path: owner-doc Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id RAA23324 for doc-outgoing; Thu, 25 Jan 1996 17:17:25 -0800 (PST) Received: from nomad.osmre.gov (nomad.osmre.gov [192.243.129.244]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id RAA23317 for ; Thu, 25 Jan 1996 17:17:18 -0800 (PST) Received: (from gfoster@localhost) by nomad.osmre.gov (8.6.12/8.6.9) id UAA16868; Thu, 25 Jan 1996 20:10:35 -0500 Date: Thu, 25 Jan 1996 20:10:35 -0500 From: Glen Foster Message-Id: <199601260110.UAA16868@nomad.osmre.gov> To: stesin@elvisti.kiev.ua CC: doc@freebsd.org In-reply-to: <199601251556.RAA00921@office.elvisti.kiev.ua> (stesin@elvisti.kiev.ua) Subject: Re: Frustrated....doc@freebsd.org Sender: owner-doc@freebsd.org Precedence: bulk > From: "Andrew V. Stesin" > Date: Thu, 25 Jan 1996 17:56:17 +0200 (EET) > > What's interesting: while sd1 was a fresh-formatted disk, > dd worked Ok, I made an initial copy of rsd0c to rsd1c > easily (fast!). But now I can't dd my rsd0a to rsd1a -- dd fails > telling me that rsd1a is read-only file system. ??? > rsd0e to rsd1e works fine! A day of beating and RTFMing > with zero result. But this belongs to questions@freebsd.org, > I'll ask there later... or learn how to "dump (1)", at last :) I found dd to be very slow, I didn't play with the bs parameters as I also ran into the "r/o" issue that you did once the part. had data on it. I find that a dump|restore pipe is much faster than dd plus the two partitions don't have to be identical. OTOH, the destination partition has to be mounted, like: # newfs /dev/rsd1h # mount /dev/sd1h /mnt # dump 0f - /dev/rsd0h | (cd /mnt ; restore rf -) # umount /mnt > Do you mean "partitions" to be fdisk partitions (those called > "slices"), or a BSD subpartitions with file systems? > I recall that there _is_ a limit on BSD subpartitions quantity > somewhere, though I'd never reached it :-) I meant "traditional" BSD (sub-)partitions whether living inside a slice or on the disk itself. These are limited to eight. Unfortunately, the sysinstall program enforces its own lower limit even though you have more than one disk and/or partition selected. I was told that there is documentation about this, perhaps in the sysinstall help files, but I haven't confirmed it myself. I like your solution for implementing a "hot spare" disk in the box, the only concerns I would have about that would be that added heat might shorten the life of both disks and that a power problem (e.g. lightning strike) could kill both disks at once.