bootable flash for centos 7

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kbr
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Joined: 2019/05/21 18:44:41

Re: bootable flash for centos 7

Post by kbr » 2019/05/22 14:30:35

Well for me personally if it solves my problem then it's the right tool for the job. LibreOffice is a bad example because it consistently mangles both plaintext and .docx files. But again, nobody's saying you can't use win32 disk imager, if for some reason you find it more suitable.

Edit: Without specific examples, it seems primarily opinion-based to state one is better than the other. Do you have any specific examples of a case of a particular CentOS ISO that worked on win32 disk imager, but didn't work using Rufus, when you tried to install it on a particular model of server/desktop/laptop?

owl102
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Re: bootable flash for centos 7

Post by owl102 » 2019/05/22 18:48:45

kbr wrote:
2019/05/22 14:30:35
Do you have any specific examples of a case of a particular CentOS ISO that worked on win32 disk imager, but didn't work using Rufus, when you tried to install it on a particular model of server/desktop/laptop?
Yes.

Just make a quick search in this forum (and in the Fedora forum and in the Debian forum and...) and you'll find such instances. Furthermore I often join meetings of my local Linux group, and we often had to fix Rufus problems, too. (Usually Linux was installed in BIOS/CSM mode since Rufus broke UEFI support of the ISO, and therefore dual boot with MS-Windows did not work via Grub.)
Last edited by owl102 on 2019/05/22 21:04:06, edited 1 time in total.
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TrevorH
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Re: bootable flash for centos 7

Post by TrevorH » 2019/05/22 19:32:22

For a Windows machine I would recommend using rawrite2 if dd is not available. We have a link to a known working copy in our wiki USB install page. Information on USB key based installs can be found at http://wiki.centos.org/HowTos/InstallFromUSBkey. It does one thing - it copies disk images to disk. It doesn't modify them and it's been working since 3.5" floppies were a thing.
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kbr
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Re: bootable flash for centos 7

Post by kbr » 2019/05/22 19:58:43

owl102 wrote:
2019/05/22 18:48:45
Yes.

Just make a quick search in this forum (and in the Fedora forum and in the Debian forum and...) and you'll find such instances. Furthermore I often join meetings of my local Linux group, and we often had to fix Rufus problems, too. (Usually Linux was installed in BIOS/CSM mode since Rufus broke UEFI support of the ISO, and therefore dual boot with MS-Windows did not work.)
Ok, so to confirm, you have the examples, but you are not willing to link them or be in any way specific other than listing a number of distros. However, you are willing to take the time to keep responding to this post.

I'd say if there is an actual problem with rufus, be specific, state which computers/setups it failed for. If we compile this information I can even make a bug report on the rufus repository, as it is currently being actively developed. Maybe the problem would even get fixed if you were interested in providing specific failure cases (i.e. an instance where running rufus in the correct mode creates a non-working ISO).

Disclaimer: I am not a developer for rufus or in any way affiliated with their project, but I am opposed to people bashing open-source projects in a non-constructive way. Furthermore it is completely inaccurate to call a project *obsolete* when it:
  • Successfully creates an ISO for CentOS 7
  • Supports a large number of Linux distros
  • Is being actively developed (latest commit 22 hours ago)

owl102
Posts: 357
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Re: bootable flash for centos 7

Post by owl102 » 2019/05/22 21:42:30

kbr wrote:
2019/05/22 19:58:43
Ok, so to confirm, you have the examples, but you are not willing to link them or be in any way specific other than listing a number of distros. However, you are willing to take the time to keep responding to this post.
And you are willing to take the time to keep responding, too, but are not willing to search for "Rufus" in Linux forums.

However, I will collect some threads on the week-end and/or will do own tests. (Sorry, I don't have time for this during the week-days.)

In the meantime I would like to quote from https://wiki.centos.org/HowTos/InstallFromUSBkey:
https://wiki.centos.org/HowTos/InstallFromUSBkey wrote: Rufus (may depend on options selected, there have been reports of failure with rufus too)
especially the "there have been reports of failure" part of it.
but I am opposed to people bashing open-source projects in a non-constructive way.
IMHO you are missing the point here. This has nothing to do with bashing. Rufus was a very useful tool in the past, and it was necessary to use tools like Rufus or Unetbootin to get booting USB sticks. I have used them myself with success, and I was very glad that these tools exist. But since all Linux ISO are hybrid ISO now the main functionality of these tools (means: writing a modified version of the ISO to the USB stick) is simply not needed anymore, instead, it could break things.

For this reason I call tools like Rufus obsolete, at least when it comes to writing Linux ISO to a USB stick. Again, this has nothing to do with bashing, and this does not make them bad tools. One of the main reasons for their existence has gone, it's simply that. You only need such tool for non-hybrid ISOs, i.e. very old versions of CentOS, Fedora, Debian etc.

Furthermore I tend to differ about "using" and "recommending". There are a lot of tools I use and like, but I would not recommend them to (new) users. For me Rufus fits into this category, too, since the easiest and safest way to get a 1:1 copy of the ISO to the USB stick is by using a tool which just does this. So even if I would use Rufus myself, I would not recommend it, but instead recommend tools like Win32 Disk Imager or the Fedora Media Writer.

Writing a bug report seems useless to me since Rufus modifies the ISO on purpose. That's its job and that was the reason why Rufus was written in the first place. Fixing this would mean stripping Rufus down to a simple 1:1 copy application, or at least hide all options which do modify the ISO behind a "expert mode" button or menu.
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owl102
Posts: 357
Joined: 2014/06/10 19:13:41

Re: bootable flash for centos 7

Post by owl102 » 2019/05/27 12:04:16

I gave an intern the job to put a CentOS 7 Minimal ISO on two USB sticks, one using Win32 Disk Imager and the other one using Rufus with default settings, i.e. loading the ISO and putting it onto the stick without changing any parameters in Rufus. Afterwards I have read back the ISO from the USB drives and have checked the sha256. The result:

Code: Select all

# dd if=/dev/sdb of=CentOS-7-x86_64-Minimal-1810-Rufus.iso bs=1M count=918
...
# dd if=/dev/sdb of=CentOS-7-x86_64-Minimal-1810-W32DI.iso bs=1M count=918
...
# sha256sum CentOS-7-x86_64-Minimal-1810*
38d5d51d9d100fd73df031ffd6bd8b1297ce24660dc8c13a3b8b4534a4bd291c  CentOS-7-x86_64-Minimal-1810.iso
6768b216d8745f0398e8d1de54db961500a38bf3bf10ee74beac10d461ecdd21  CentOS-7-x86_64-Minimal-1810-Rufus.iso
38d5d51d9d100fd73df031ffd6bd8b1297ce24660dc8c13a3b8b4534a4bd291c  CentOS-7-x86_64-Minimal-1810-W32DI.iso
# more sha256sum.txt 
..
38d5d51d9d100fd73df031ffd6bd8b1297ce24660dc8c13a3b8b4534a4bd291c  CentOS-7-x86_64-Minimal-1810.iso
...
So Rufus has altered the contents of the ISO before writing it to the USB stick. Furthermore the media check will be skipped (with an error message? It happens to fast too for reading the message) when booting the stick written by Rufus. I haven't check the installation from USB since the altered ISO and the missing media check is sufficient to not recommend Rufus, at least for me.
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