Tim wrote:
imalone:
How would you go about estimating a decent blocksize (other than by
testing)? My first instinct would be to go for some percentage of
the drive's cache.
Jacques B:
Available RAM. Use as big a block size as can possibly be read into
RAM (once you start caching to a drive you just as well be writing to
the destination drive otherwise you slow it down even more).
The discussion of block size says your in a hurry to do it. Here is
a modified HowTo for dd.
If you want to copy something big from one partition to another the
old dd method is for you. You have to do it right. This means that:
1. The destination partition MUST be at least a byte larger than the
source partition where the data is coming from. This is essential!
2. The dd copies everything including the file system.
3. Be ready to check the file system of the copy with fsck.
4. If you are making a copy of an entire working Fedora system make sure
you change all the entries in /etc/grub.conf and /etc/fstab files to the
new partitions of the copy before you try to run it.
5. To copy a partition from the source, called /dev/source to a
destination partition called /dev/destination use the standard dd form:
# dd if=/dev/source of=/dev/destination
6. Make certain that all Hard Drives are registered in bios. Put the F7
Rescue CD in, or your F7 DVD in, and select Rescue. When it asks if you
want to mount your fedora system do not just go to the Prompt. At the
prompt do your dd transfer.
7. Take your time doing all this. It will save you problems later. There
are a lot of ways to make errors.
8. Think of how dd works this way, dd see's the source partition as just
a pile of bytes. It takes a few bytes each cycle and puts those bytes on
the destination partition. When done dd reports how many bytes it found
and how many it put on destination. They are the same large number.
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
