Date: Mon, 30 Sep 2002 19:10:06 -0500 From: "Jack L. Stone" <jackstone@sage-one.net> To: "Pranav A. Desai" <pdesai1@cs.uh.edu>, <freebsd-questions@FreeBSD.ORG> Subject: Re: how to use 'dd' to create image of a hard drive? Message-ID: <3.0.5.32.20020930191006.028ece30@mail.sage-one.net> In-Reply-To: <Pine.GSO.4.33.0209301830510.1900-100000@themis.cs.uh.edu> References: <3.0.5.32.20020930181112.028ece30@mail.sage-one.net>
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At 06:39 PM 9.30.2002 -0500, Pranav A. Desai wrote: >Hi ! > > Thank you all for your prompt replies. You have said in your >replies that the bs parameter should be set appropriately. Is there a way >to find out appropriate block size, or any reasonable size should do, like >1k or 4k. I am asking because I tried it a few weeks ago and I was unable >to mount the new drive let alone boot from it. Mostly I must have done >something wrong. I dont have access to another drive or else I could have >tried it again. Let me know if any block size will do or should it be >specific. > >Thanks >-Pranav > >******************************************************************* >Pranav A. Desai > >Home :- (937) 294 1381 >******************************************************************* > >On Mon, 30 Sep 2002, Jack L. Stone wrote: > >> At 04:02 PM 9.30.2002 -0700, David Smithson wrote: >> >> >> >Hi all! >> >> >> > >> >> >> > Can I use something like >> >> >> > >> >> >> >dd if=/dev/ad0 of=/dev/ad1 >> > >> >Yes. This will work fine. >> > >> >> NO! An entire image is taken of the ad0 and no labeling is necessary. It >> >is >> >> bootable already. >> >> >> >> Best regards, >> >> Jack L. Stone, >> >> Administrator >> > >> >I agree with Jack. However, if you want to boot from it as "ad1" or >> >whatever, I think you'll have to tweak your bootloader settings a little >> >bit. Right? >> > >> >> Yes, or if it is for a backup for ad0, just switch the cable and reboot..... >> This should tell you: $ dumpfs /filesystem | grep '^bsize' ... and replace the /filesystem with those of your choice.... BTW, I found that I could boot right up with the bs=8192, (which was my bsize) but had to run fsck for anything different because I got warning about "not clean" on bootup. So, I booted single user and ran fsck and it cleaned right up. bs=102400 or bs=128k will dd faster though.... you can play with that. Best regards, Jack L. Stone, Administrator SageOne Net http://www.sage-one.net jackstone@sage-one.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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