Date: Sun, 21 Nov 2010 08:23:54 +0100 From: Matthias Apitz <guru@unixarea.de> To: perryh@pluto.rain.com Cc: mav@freebsd.org, freebsd-usb@freebsd.org Subject: Re: copying /dev/da0 with dd(1) to file: output differs Message-ID: <20101121072354.GA69433@current.Sisis.de> In-Reply-To: <4ce865a4.aMSvcjRoHgImeAYF%perryh@pluto.rain.com> References: <201011191916.53655.hselasky@c2i.net> <mailpost.1290191957.493865.17097.mailing.freebsd.usb@FreeBSD.cs.nctu.edu.tw> <4CE6C73A.4070208@FreeBSD.org> <20101120151655.GA4010@current.Sisis.de> <4ce865a4.aMSvcjRoHgImeAYF%perryh@pluto.rain.com>
next in thread | previous in thread | raw e-mail | index | archive | help
El día Saturday, November 20, 2010 a las 04:19:48PM -0800, perryh@pluto.rain.com escribió: > ... > > What does this mean? Does not look like errors, in case of random > > error it whould be more caotic, or? > > Good question. > > To help sort out whether it matters, what happens if you read the > stick using dump(8) instead of dd (or mount it read-only and read it > with tar)? Either of those methods will read only the parts that > are in use. Good idea! A dump is fine and gives more or less the same size as the dump which was restored to the USB key: # dump -0au -f reRead.dmp /dev/da0s1a DUMP: Date of this level 0 dump: Sun Nov 21 08:05:25 2010 DUMP: Date of last level 0 dump: the epoch DUMP: Dumping /dev/da0s1a to reRead.dmp DUMP: mapping (Pass I) [regular files] DUMP: mapping (Pass II) [directories] DUMP: estimated 3282758 tape blocks. DUMP: dumping (Pass III) [directories] DUMP: dumping (Pass IV) [regular files] DUMP: 56.62% done, finished in 0:03 at Sun Nov 21 08:14:18 2010 DUMP: DUMP: 3287561 tape blocks on 1 volume DUMP: finished in 586 seconds, throughput 5610 KBytes/sec DUMP: level 0 dump on Sun Nov 21 08:05:25 2010 DUMP: Closing reRead.dmp DUMP: DUMP IS DONE current# ls -l reRead.dmp ~guru/usb9root.dmp -r--r--r-- 1 guru wheel 3351920640 12 nov 13:40 /home/guru/usb9root.dmp -rw-r--r-- 1 root wheel 3366461440 21 nov 08:15 reRead.dmp One could as well MD5 compare all files with find(1), but this is perhaps a bit overkill... I will buy a 2nd key and restore the dd(1)'ed file to it with dd(1)... matthias -- Matthias Apitz t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e <guru@unixarea.de> - w http://www.unixarea.de/
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20101121072354.GA69433>