Re: lazy old guy asks question
On 8/28/25 21:55, David Christensen wrote:
On 8/28/25 16:52, mick.crane wrote:
If I've got 3 200Gb disks that are working and one 1 Tb disk and want
to be able to copy and replace the 3 disks.
Can I dd copy them to .isos on the 1 Tb disk then put them back on
other disks so they boot?
Copy them to 3 partitions on the 1 Tb disk and dd an individual
partition to another disk and have it boot?
mick
Please clarify:
1. What is currently on the three 200 GB disks?
2. What do you want on the 200 GB disks when you are done?
3. What is currently on the 1 TB disk?
4. What do you want on the 1 TB disk when you are done?
5. The "other" disks contain nothing of value and can be zeroed?
6. How many "other" disks do you have?
7. What are the size(s) of the "other" disks?
8. What do you want on the "other" disks when you are done?
Please answer the above questions. This will help clarify what you
have, what you want, and what solutions make sense.
On 8/29/25 02:55, mick.crane wrote:
> I apologise for not being clear in my question I should know by now
> not to post if "tired".
> For the purpose of backing up 3 ~200Gb disks, with Debian operating
> systems on them, I wondered if I can put them all on one 1Tb disk and
> be able to copy them back.
First, backup your data.
I use the following terms for what you describe:
* "cloning" -- copying all or part of the bytes on a raw disk to another
raw disk.
* "imaging" -- copying all or part of the bytes on a raw disk to an
image file (backup) or vice-versa (restore). Image files typically have
the extension "img".
While it is possible to use a terminal and command line utilities to
accomplish cloning and imaging, it requires a lot of knowledge and the
work is tedious. I started this way back in the day. Over time, I
wrapped the commands in a Perl script and added more commands --
compression, checksums, and verification. It works, but is not standard
sysadmin kit.
Clonezilla is the canonical FOSS power tool for cloning and imaging, and
is standard sysadmin kit. If I were learning cloning and imaging today,
I would start with Clonezilla:
https://www.clonezilla.org/
> Not really understanding how dd works wondered if a bootable disk can
> be copied to a partition on another disk for the purpose of backup.
In the context of cloning and imaging, dd(1) is used to move bytes from
raw disk to raw disk, from raw disk to image file, and from image file
to raw disk. dd(1) has many features beyond cloning and imaging.
I would call putting the contents of one disk into a partition on
another disk a variation of "imaging", but the image is stored in a
partition rather than in a file. That would be confusing, which means
it would be easy to damage the image during later operations or maintenance.
On 8/29/25 06:02, mick.crane wrote:
> I have my data on a separate disk that I copy to various places every
> now and again.
Multiple copies of a given file is likely to cause confusion and data
loss. A file server or NAS allows for centralized access to a
definitive copy of each file. A networked version control system allows
for multiple working copies of files and provides a form of backup/ restore.
> I guess simplest is original plan ( as have been previously given the
> incantation ) to get 3 ~200Gb disks and dd to them.
Please clarify your goals and what commands you plan to use.
David
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