Thanks for that reply, Felix.
It looks like our best solution is to try to learn the
drive models or cyl/sect/head counts of the various drives
we may be seeing, and ideally create a master image on
the smallest one. If we can't get a hold of the smallest
one in advance, we'll just create partition sizes as if
we were working on the smallest geometry and then image
that and live with an error from udpcast (which would
be something like "no space left on device"?).
On Wed, 26 May 2004, Felix Rauch wrote:
On Wed, 26 May 2004, Donald Teed wrote:
Assuming that most data will be packed in the
the drive (we use Ghost on the template development machine,
which should be doing a defrag as it makes its image),
how can there be any data loss if there is a small difference
in size between two models of drive?
Even if you do not have data in your last few blocks initially, your
file system might still try to write some blocks there at some later
point in time. This does not necessarily only happen when the disk is
full. It depends on the algorithms of your file system and on the
The alternate paranoid approach is to make an
for every model of drive involved. If there is no real
need to do that, we'd like to avoid the extra efforts
involved in making a new image file each time a new
model of drive is encountered.
You could partition your drives in such a way that you do not allocate
more blocks than are available on your smallest drive. Leave all the
superfluous blocks unallocated, i.e. unpartitioned.
That way you might still get errors when cloning the full disk (that
might depend on your cloning tool), but the file systems on your disks
are nevertheless fully cloned.
Felix Rauch | Email: rauch(a)inf.ethz.ch
Institute for Computer Systems | Homepage: http://www.cs.inf.ethz.ch/~rauch/
ETH Zentrum / RZ H16 | Phone: ++41 1 632 7489
CH - 8092 Zuerich / Switzerland | Fax: ++41 1 632 1307