Date: Mon, 12 Aug 2002 13:05:50 -0700 From: richard childers <fscked@pacbell.net> To: pg@eth1.com Cc: freebsd-mobile@freebsd.org Subject: Re: dumping entire ide laptop disk Message-ID: <3D58151E.62D3D51C@pacbell.net> References: <20020812182323.53681.qmail@web9705.mail.yahoo.com>
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Peter Gatsoulis writes:
"... some of the fs are not Unix filesystems but MS DOS and NTFS
does dump work with non-unix fs'es?"
No, dump only understands the UNIX 4.2 Fast File System and
derivatives.
(Looks for entry-level page describing FAT filesystem and permutations
...)
A good place to start:
http://www.systweak.com/fat32/fat12.htm
Some sales literature that touches on how many friggin' filesystems
there are:
http://www.webfs.com/shared/papers/gfss_paper.pdf
How I found these two gems:
http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=FAT+FAT32+NTFS+UFS+differences
"if i want to dump ALL the partitions into 1 file per
disk, without mounting each disk? is this possible?"
Theoretically, yes; as you noted, you could use dd(1) to dump a raw
image of the partition. It's not clear if that data, when restored to
another partition, would be usable ... and note that there are no error
detection mechanisms in dd(1), so you could easily copy a bad block, as
is, and not record the information which elsewhere noted that this was a
bad block - for instance.
Basically, you can think of backups as available at a variety of
granularities. You can operate upon simple files (IE, 'cp file
file.BAK'), or you can operate upon entire directories of files (IE,
'tar cvf /tmp/foo.tar /my/dir/'), or you can operate upon entire
filesystems (IE, 'dump 0f /dev/rmt8 /dev/sd0a'), or you can operate upon
raw partitions (IE, 'dd if=/dev/sd0a of=/dev/sd1a bs=512b'). Some of
these methods add more value than others - at the high end, dump(8)
preserves inode information so that a carefully crafted filesystem with
special inode characteristics can be preserved and restored ... at the
low end, dd(1) just reads and writes bytes and does some optional
operations on them, en passant.
dd(1) is so non-discriminatory that it *could* be used to back up NT
partitions. Sure, you also *could* use it to back up raw Oracle
partitions. But why, when there are perfectly good utilities that do a
better job and add more value?
I would strongly recommend using native utilities to copy your
installations and not assume that you can move Windows installations
about, willy-nilly. Registry entries on PCs running Windows, detailing
every little device driver and interrupt, make it very hard to achieve
true portability between machines ... never mind portability of
filesystems under those Windows operating systems.
You may want to look into using some sort of ZIP utility to make an
archive of your Windows installations, and use a Samba server as a
temporary holding place for those ZIP files while you are rebuilding
your machine; this would give you the backups you desire, along with
error-checking and considerable flexibility in terms of what you
restore.
"as it is now, i am NOT mounting the disk, and i have
tried listing the partitions in many ways, /dev/ad3s1,
/dev/ad3s1a, /dev/rad3s1e etc ..
what would be correct syntax? if this is not?"
Lacking more information or a proper listing of all the relevant device
entries you have before you it is hard to guess.
However, I seem to recall, when I was experimenting with FreeBSD's
capacity to mount DOS and NTFS filesystems (note that I mounted them
read-only, and I suggest this to everyone - why do you NEED to write to
your idle NTFS partition, no, of course, you don't, you just need to
read or copy something, right?), that the 'D' partition was reserved for
DOS. Have you tried mounting /dev/ad3s1d, ad3s2e, ad3s3e?
A better description of the exact disk, its exact physical geometry, and
how it's been sliced would be useful; personally, I always dedicate my
entire drive to FreeBSD, these days (easier to carry two laptops, you'll
probably need access to them both at the same time anyway), and so my
understanding of slicing is a bit fuzzy.
-- richard
c/o Peter Gatsoulis wrote:
> Thank you but some
>
> of the fs are not Unix filesystems but MS DOS and NTFS
> does dump work with non-unix fs'es?
>
> if i want to dump ALL the partitions into 1 file per
> disk, without mounting each disk? is this possible?
>
> as it is now, i am NOT mounting the disk, and i have
> tried listing the partitions in many ways, /dev/ad3s1,
> /dev/ad3s1a, /dev/rad3s1e etc ..
> what would be correct syntax? if this is not?
> thanx
> --- richard childers <fscked@pacbell.net> wrote:
> > Peter Gatsoulis writes:
> >
> > "i remove the drives and mount them in a desktop by
> > using a 2.5"-3.5" IDE adapter, the desktop boots
> > fine
> > and reckognizes the new drive as ad3
> >
> > "i now try;
> > dump 0f - /dev/ad3 |bzip2
> > -c>/somemountpoint/somefile
> >
> > "i get, "bad sblock magic number" and entire dump
> > aborts."
> >
> > I would try to mount the filesystem and run 'fsck
> > -p' on it first before
> > I would dump it. This would insure that you had the
> > correct device name,
> > if you were able to fsck or mount the filesystem.
> >
> > That having been said, note that the first example
> > you cite refers to a
> > "/", IE, dump(8) infers the device name from the
> > mount point. If it is
> > not mounted, you need to supply the correct device
> > explicitly, and
> > "/dev/ad3" is insufficient.
> >
> > In the past when I have had to recover trashed UNIX
> > boxes where the
> > /etc/fstab has been lost or mangled, I have found it
> > useful to do
> > something like:
> >
> > # /bin/csh
> > # foreach dev ( `ls /dev/*sd*` )
> > ? echo "${dev}"
> > ? echo ""
> > ? fsck -n ${dev}
> > ? echo ""
> > end
> >
> > ... and in this way, one can quickly identify which
> > /dev entries
> > correspond to file systems (and perhaps even learn
> > where they were last
> > mounted :-).
> >
> > Hope this helps.
> >
> >
> > -- richard
> >
> > c/o Peter Gatsoulis wrote:
> >
> > > hello & pls Help .?
> > >
> > > In the past w/ help from this list's members the
> > > following has worked GREAT:
> > > (using FBSD 4.5 but works w/ all FBSD versions)
> > >
> > > dump -0 -f - /|bzip2 -c>/mnt/where-ever/foo.dump
> > >
> > > used this continuosly to backup filesystems, but
> > NOW i
> > > have some laptop drives w/ mixed fs, ie: 1st
> > partition
> > > can be MS DOS, 2nd partition can be NTFS, 3rd
> > > partition can be ufs w/ softupdates.
> > >
> > > i remove the drives and mount them in a desktop by
> > > using a 2.5"-3.5" IDE adapter, the desktop boots
> > fine
> > > and reckognizes the new drive as ad3
> > >
> > > i now try;
> > > dump 0f - /dev/ad3 |bzip2
> > -c>/somemountpoint/somefile
> > >
> > > i get, "bad sblock magic number" and entire dump
> > > aborts.
> > >
> > > reading the FBSD handbook, dump manpage and
> > searching
> > > the archives leads me to believe that dump can
> > indeed
> > > backup entire disks, irrespective of which fs is
> > on
> > > disk???
> > >
> > > i've tried specifying ad3s1, ad3s1a, rad3s1e etc,
> > many
> > > variations of specifying device name BUT same
> > > results..
> > >
> > > how can i use dump to "snap" the entire disk
> > image?
> > > don't want to use dd in case i have to restore to
> > > another diffrent laptop & drive ...
> > >
> > > __________________________________________________
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> > >
> > > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > > with "unsubscribe freebsd-mobile" in the body of
> > the message
> >
> > --
> >
> > Richard A Childers/KG6HAC -- Senor UNIX System &
> > Network Administrator
> > "Dont forget nothing." Maj Rogers, standing orders,
> > 1st Ranger Bn, 1759
> >
> >
> >
> > To Unsubscribe: send mail to majordomo@FreeBSD.org
> > with "unsubscribe freebsd-mobile" in the body of the message
>
> __________________________________________________
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--
Richard A Childers/KG6HAC -- Senor UNIX System & Network Administrator
"Dont forget nothing." Maj Rogers, standing orders, 1st Ranger Bn, 1759
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