At 05:25 AM 11.15.2002 +0100, Mark wrote: >----- Original Message ----- >From: "Jack L. Stone" <[EMAIL PROTECTED]> >To: "Mark" <[EMAIL PROTECTED]>; "Matthew Emmerton" ><[EMAIL PROTECTED]>; "R. Zoontjens" <[EMAIL PROTECTED]>; ><[EMAIL PROTECTED]> >Sent: Friday, November 15, 2002 2:57 AM >Subject: Re: restore question > > > >> There IS a program similar to Ghost with respect to making an image. >> It's called "dd" and it's already installed on your FBSD system. >> Run "man 1 dd" for options. >> >> Bear in mind that if you want an image of your whole disk, you'll need >> the 2nd one to be at least equal in size, but you will lose any part of >the >> 2nd HD that is larger than HD #1 (I think Ghost does that too >> -- or used to). dd can be limited to imaging only a slice however..... >> >> This questions comes up monthly and the archives has numerous postings >> over the past several months that will fill more details..... > > >Yes, the question comes up many times; yet the right answer keeps lacking. >:) Before I asked, I had, of course, done a bit of searching. And found that >there are many disadvantages to using "dd". > >For one, using disk-blocks, instead of reading files sequentially, like tar >and Ghost do, enhances the risk of data-corruption. > >For two, with "dd" you need to unmount filesystems first. Which makes it >pretty useless on a production server. Yeah, like I can really afford to >have my /usr slice be absent for half-an-hour. I think not. :) > >Actually, we are talking about backup, but the real issue is restore. >Everybody can make a tar of the root system, or a dd image. Sure. Restoring >it, however, in a manner that will yield you a bootable, instant runnable >system, now that is another matter. And what to do with special cases like >/dev? > >In all my perusing the net, I have yet to encounter one solution that said: >"This is how you can make a full system backup, with this image, that you >can immediately restore on a blank harddisk, and have your system up and >running again." > >Many suggestions I read about ways to backup. But, like I said, restoring is >the real issue. I can backup /proc for sure; the wisdom of restoring it on a >life system, however, is another matter. That is why the only clean way of >doing this, would be to make a disk-image, like Ghost does. And Ghost, so >unlike dd, does NOT use disk-blocks, but reads files sequentially. When >making a disk image, Ghost basically just does several partition images, and >then adds partition table info to the overall disk image. No need to "zero" >out the disk first, like with dd, so as not to have it waste too much space. > >Still looking... > >- Mark >
I missed this earlier. You say: "That is why the only clean way of doing this, would be to make a disk-image, like Ghost does." I'm unaware of any backup that takes longer than a nanosecond where files will not have changed on a system by the time you are done making an image. Does Ghost sync the files again at the end of the backup....??? I am not anti-Ghost, just pro-dump/retore and dd after that and tar after that...... because I feel I can trust them with my data. Best regards, Jack L. Stone, Administrator SageOne Net http://www.sage-one.net [EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-questions" in the body of the message
