Date: Fri, 15 Nov 2002 10:58:14 -0500 (EST) From: Jerry McAllister <jerrymc@clunix.cl.msu.edu> To: hymette@wanadoo.fr Cc: freebsd-questions@FreeBSD.ORG (freebsd-questions) Subject: Re: How to backup a disk ? Message-ID: <200211151558.gAFFwE325204@clunix.cl.msu.edu> In-Reply-To: <3DD4AE2A.7000704@wanadoo.fr> from "hymette@wanadoo.fr" at Nov 15, 2002 09:19:54 AM
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>
> hi,
> I have a 6G disk and a 40G disk on which FreeBSD is installed. My system
> does not fill 6G yet and I'd like to copy it to the smaller disk before
> it grows. But I would like to have the copy bootable with preserved
> privileges UIDs and GIDs, only the fstab changed. Which tools could I
> use to get this backup?
First, I am presuming there is nothing you want to save on the small disk
(or you have already preserved it somewhere).
While booted to FreeBSD
Used fdisk(8) to create one large FreeBSD slice on the small disk.
fdisk -IB da1 (or ad1 or whatever device the disk is)
will slice the disk and put a standard boot sector on it.
Then use disklabel(8) to initialize the slice and add boot blocks
disklabel -w -r -B da1s1 (or ad1s1 or whaever)
Then use disklabel to edit the partition table on the slice
Look at what you already have to figure out appropriate sizes.
disklabel -e -r da1s1 (ad1s1 or watever)
add the partitions as needed. Note the size is in 512 byte blocks
Put '*' in for offset for all but partition a: and c: so disklabel
will calculate offset for you. For a: and c: put in '0'.
Take the defaults for fsize (1024) bsize (8192) and bps/cg unless you
really want to play with that.
Omit the comments at the end of the line after #.
Partition c: is the whole slice and is type 'unused'
partition b: will probably be swap and is type 'swap'
The remaining partitions will be files systems and type '4.2BSD'
Finally, run newfs on the newly created partitions, something like:
newfs -b 8192 -f 1024 /dev/rda1s1a (or Rad1s1a or whatever)
"" "" "" "" "" e
etc
Don't newfs the swap partition or the c: partition
Make mount points for the new partitions
cd /
mkdir newpa
mkdir newpe
etc
Edit fstab to add entries for the new partitions and mount them
/dev/da1s1a /newpa ufs rw 2 2
/dev/da1s1e /newpe ufs rw 2 2
etc
mount -a
or just manually mount them
mount /dev/da1s1a /newpa
mount /dev/da1s1e /newpe
etc
Now you can dump restore
cd /newpa
dump 0af - / | restore rf -
cd /newpe
dump 0af - /prev_e_mount_pt | restore rf -
etc
Now, shutdown your system, swap the drives and reboot.
If you made the partitions identical (in name eg a,b,e,f,etc, not size)
and edited /etc/fstab before dumping root then it should all come up
with running on the new smaller disk and with the old large disk
mounted on the /newpa, /newpe, etc mount points.
Note that everything but the dump /restore can be done ahead of time.
If you are really worried about losing some thing, you will want to
do the dump/restore part in single user mode.
So, after getting all the partitions made and editing /etc/fstab.
Shutdown/reboot, come up in single user mode.
Then do
fsck -p
mount -u /
mount -a or maybe mount -a -t ufs,nonfs if you have nfs mounts in fstab
swapon -a
Then do the dump/restore operations as indicated above.
Then, shut down, sap drives and reboot.
////jerry
>
> Thank you in advance.
>
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