[lug] Backup to 2nd HD with dd & rsync?

[Nate Duehr]

Just thoughts... no random order, brain-fried on a Friday afternoon after
fighting with OpenSSL all week... (I hate SSL client authentication...
someone please shoot me.)

SCSI handles the MBR differently with the whole initial ramdisk (mkinitrd)
thing... the IDE probably won't boot properly after a dd from the SCSI, but
never tried it.

I have seen this done successfully between two identical IDE disks.  Nightly
dd to an OFFLINE/not mounted IDE disk... swap the primary and secondary,
you're back to last night... there were a few issues with open files, of
course...  quieting the filesystem or even dropping to single-user mode
before doing this might be adviseable.

Almost beer-30... TGIF!

Nate Duehr, nate at natetech.com

----- Original Message -----
From: "D. Stimits" <stimits at attbi.com>
To: <lug at lug.boulder.co.us>
Sent: Thursday, January 23, 2003 8:07 PM
Subject: Re: [lug] Backup to 2nd HD with dd & rsync?


> Thomas R. Detman wrote:
>
> > I have two hard disks spinning in my workstation.
> > I would like to use one as a backup for the other,
> > --> if it isn't too too complicated.
> > One is a SCSI and the other is IDE.  (A result of history, not plan.)
> > The SCSI is the one I use, it is 17 GB, ext3, with 4 partitions.
> > The IDE could be wiped. It is 12 GB, ext2, with 2 partitions.
> > Every thing stored on the SCSI only takes up only 10.5 GB.
> >
> > Me thinks I'de start by using dd to copy the "stuff" on the SCSI
> > onto the IDE, wiping out previous IDE contents in the process.
> > (Doing such "stuff" is outside my envelope of knowledge and comfort.)
> >
> > Next I'de set up a cron job to keep the IDE drive up to date as
> > a "mirror" of the SCSI drive using rsync.  The rsync web page:
> > http://rsync.samba.org/ seems to suggest this is just the kind of
> > thing rsync was made for.
> >
> > I think I might be able to muddle thru the rsync part, but even
> > after reading the man and info pages on dd, it still seems like
> > black magic to me.
> >
> > Tom
> > _______________________________________________
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> Won't work right if the drive that is the source is mounted at the time
> and changing in any way. You'd also want to dd the 512 bytes of the MBR
> and any PBR. You could remount read-only and probably get away with it.
>
> D. Stimits, stimits AT attbi DOT com
>
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