Creating images using disk utility

[jangu23]

Hi community,

my macbook pro can't boot up at all so I need to use macRecovery (cmd+R when turning on) and reinstall High Sierra from there. However, I'm concerned that doing so will delete my files on the HD.
Unfortunately, I never once used TimeMachine. So I decided to use DiskUtility (DU), also accessible via macRecovery. This way I want to create images (dmg files) of specific folders of mine.
Please note that I am able to access the macR options without typing in my password.
I have several questions on this topic, as I am using it for the first time, and since the files are somewhat valuable to me I do not want to risk anything.

1) When using the file browser (using the create image from folder option) I can see that my files are still there. I can even right click them. This "allows" me to move them to trash, duplicate or view them. Actually, none of this options works. When trying to view a file or folder (also using the spacebar) then DU is quitted and I'm teleported bad to macR menu. Is this intended ? Is there any other way to view or delete ? These functions would be very usefull.

2) Similar to 1) I can click on files and drag the around, hovering them over external drive like USB will make the green cross (copy symbol) appear but unpressing the mouse will result in nothing to happen ? Is it OK or do I really have the possibility to copy files directly instead of making images ?

3) I only want to extract files from the dmg's once I installed the OS and can properly use may mac again. I do not need encryption. What is the fastest option to create the images then ? The options are
read only
compressed
read/write
DVD/CD master
hybrid image (HSF+/ISO/HFD)
Can I achieve larger speeds with blank images (if I can actually fill them with files in the current stat of my mac which I don't know -.-)

4) I have the possibility to transfer the images from USB to a pc on my workplace, to have more storage space. I might be interested to also open the image files on that pc which runs on windows but where I cannot install external software (workplace ...). Can I create such images with DU ? Does this make the creation process much slower than read only or compressed ?

5) When I tried to create a image from folder which I roughly calculated would fit very well on the USB (10GB vs 25GB) after waiting like 1.5hours for the creation the process stopped saying "File too large". What's the problem ?


Suggestions what to do to save the files would be useful, too. I'm really desperate right now :/

Regards

 

[Lufbrarunner]

and since the files are somewhat valuable to me I do not want to risk anything.

So the files have some value to you, but you have not backed them up or made copies of them?

 

[jangu23]

So the files have some value to you, but you have not backed them up or made copies of them?

No, I've never touched TimeMachine or the like, only some files were saved on USB. Dumb, I know
Fortunately, the files of value are not that many, which is why I can use the "Image from folder" option.

 

[jangu23]

To expand this, here's my backstory:
I tried to install High Sierra, but the installation failed somehow. From then on I turn on my mac, a kernel panic screen (or how you call it) appears. Under macOS version it says 'not yet set'. Then my mac shuts down and turns itself on again, the same thing repeats itself a few times.
I've been using my mac until this moment for like 3.5 years without any of such kernel panics. I was installing several updates and OS's without any problems. So I'm very confident that my HD is not damaged or failing, but the OS was installed incorrectly and that's why I'm stuck at the turn on.

What I already did was reseting some storages which names I forgot (holding cmd+alt+shift or cmd+alt+p+r while booting). Not sure if I see if that worked but this are auxiliary actions, I guess ? Booting into safe mode was not possible.

So that is how I've come to the point of reinstalling the OS (High Sierra). As said I did the first aid in DU with the above information. It doesn't seem to be broken or anything. The file browser shows that my files are still on that HD.
However, I am unsure whether my files will be kept on that HD upon reinstallation. Normally when I was installing other macOS's in the past this was always the case, like when changing the wardrobe you are not getting rid of all your clothes, right ? So I would expect for the same to happen now as well. But then again the circumstances are different as I'm installing the OS through macR without using my password.
The question above of course is asked for the case if I would have to do this. So, is there the absolute certainty that my files will get wiped when reinstalling, or is the backup per images just a precautionary measure ?

 

[jangu23]

I think I'll emphasize one question of mine. The files of interest are only few so I could simply transfer it to other computer by creating image from folder in disk utility.
Buuuut there is one problem: trying to make image from a folder that is approx 2-3GB fails, saying 'file too large', and my USB has easily enough free space. Is this really intended, and why ? Is there a way to create bigger dmg files with some options, like compressed or via blank image ? But still for the purpose of imaging specific folders, not whole HD

Regards