Ghost for FreeBSD

[Vincent Poy]

On Wed, 3 Sep 2003, Joshua Oreman wrote:

> On Wed, Sep 03, 2003 at 01:12:25PM +0000 or thereabouts, Mark wrote:
> > ----- Original Message -----
> > From: "Vincent Poy" <vince at oahu.WURLDLINK.NET>
> > To: "Mike Tancsa" <mike at sentex.net>
> > Cc: <freebsd-questions at freebsd.org>
> > Sent: Wednesday, September 03, 2003 2:22 PM
> > Subject: Re: Ghost for FreeBSD
> >
> >
> > > cd /mnt/root
> > > /sbin/dump -L -f- /|restore -rf-
> > > cd /mnt/var
> > > /sbin/dump -L -f- /var|restore -rf-
> > > cd /mnt/usr
> > > /sbin/dump -L -f- /usr|restore -rf-
> >
> > I have heard this before, but I never understand this part. :) How does
> > creating a /mnt/root directory, and restoring in that directory get my /
> > slice back? Then the restored data will just sit in /mnt/root! What good
> > does it there?
> >
> > Or should I create /mnt/root as partition, about equal in size to the root
> > partition, and then restore therein, and do the old switcheroo in /etc/fstab
> > later, to make it the root partion?
> >
> > I have successfully restored /var and /usr, on occasion; but that is rather
> > easy, as they can be unmounted. With the root partition, that is not
> > possible, of course. Short of having to switch cables on harddisks, is there
> > a software method that will allow me to restore/switch the root partion?
>
> To mirror the root partition to another:
> # mkdir /mnt/root
> # mount /dev/<ROOT-MIRROR-DEV> /mnt/root
> # cd /mnt/root
> # /sbin/dump -f- / | restore -rf-

	That was how I did it originally but dump said to add the -L flag
for live filesystems so I changed it to:

mkdir /mnt/root
mount /dev/<ROOT-MIRROR-DEV> /mnt/root
cd /mnt/root
/sbin/dump -L -f- / | restore -rf-

> You will not *need* to umount the root partition.
> (If you wanted to hot-swap between them, I'm not sure it's possible on FBSD.
>  There is a ``pivot_root'' syscall on linux, though.)

	Yep, I just do it as a script on a nightly basis and kill sendmail
before the dump/restore and then later run sendmail automatically after
the dump/restore so I don't lose anything in the dump/restore process.  I
don't think you can hotswap but /stand/sysinstall's disk labeler sure has
a way to mount the second drive if you actually put in / and /usr as mountpoints and
write it.

> To mirror another partition, do mostly the same thing, but replace /
> with the partition in the dump line (and make sure the correct
> destination is mounted on your current directory for the restore).

	Yeah, I made the mistake originally when I tested it two days ago
and put / for /mnt/usr and I noticed it dump/restore in less than
a minute and then realize I forgot to change it to /usr.

> Dump/restore is pretty much the accepted way of doing this.

	One thing I'm trying to figure out is dump will tell you to use -L
for a live filesystem but what happens if certain files change on the
original slices while it's doing the dump/restore.


Cheers,
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