<html><head></head><body><div>On Wed, 2017-08-23 at 02:07 +0000, Iznogoud wrote:</div><blockquote type="cite"><pre><blockquote type="cite">
Alternatively make an exact duplicate of your old HDD/SSD via:
# dd if=/dev/sda of=/dev/sdb bs=100M conv=notrunc
where /dev/sda is your original existing HDD/SSD
and /dev/sdb is your new blank HDD/SSD
</blockquote>
Some points to make here.
"dd" using this method is an excellent way of making backups if you do not
want to deal with bootloaders and if everything is in one partition, in this
</pre></blockquote><div><br></div><div>The dd command will make an exact copy of the input disk onto the output disk regardless of the number of partitions, it copies boot loaders and hidden partitions. it makes a bit-exact copy of the input hard disk, which is why I use it when I perform an upgrade, replace the gronked disk with the backup disk, boot and go. </div><div>About the only caveat is that the output disk needs to be *no smaller* than the input disk.</div><div><br></div><blockquote type="cite"><pre>example it would be the /dev/sda _drive_. This is how I make backups of Windows
machines or anything I do not feel like getting my hands really dirty with.
(Windows maintainers look no further.)
With a Linux, even a running system, you can make a tarball of the relevant
directories, skipping /proc /sys /srv and /tmp, and simply dropping the
contents of the tarball on any partition one wants. The final trick would be
to get GRUB or LILO dropped in the boot loader. But the tarball is very small
compared to an image drawn with dd. I do this. I install tarballs by PXE-booting
and dropping GRUB from the "thinly-booted client."
Another real issue is fragmentation... With a good filesystem, say XFS, which
can go through a swift defragmentation and re-arrangement or sizing of the file
system, you can pull the first, say, 100MBs of the partition. Not in general.
You can also mount an extrnal or internal filesystem, or even a remotely
mounted one over a fast network, and either do the tarball trick or use dd
like so: 'dd if=/dev/sda1 of=/mnt/remote_mount_file' I always prefer a tarball.
Expert users can pull files (say the /etc/ crucial parts from the old install)
by mounting the image (drawn with dd) over a loop-back block device or a
straight file-mount at a mount-point, and dig in there. (I do not expect this
kind of action from anyone but a Slackware nerd.)
Bonus. I sometimes put image-files together and encrypt them.
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</a></pre></blockquote><div><br></div><div>Usinig the tar command also enables you to split and merge parts of filesystems - things us old-fart sysadmins needed to do when production SCSI HDDs were 9GB or less each - each partition could reside on a separate HDD - i.e. /, /var, /home, etc... could each reside on their own HDD as space or inode tables filled up.</div></body></html>