My last few computers have only included CD drives for the purpose of booting installers that are inconvenient to put on USB. USB drives, on the other hand, are quite universal.
When trying to transfer an ISO to a USB stick, I find
dd if=<file> of=<device> bs=4M; sync
as per Debian wiki [1] works for me with Debian isos and recently a CentOS live CD image when installing on another laptop. Oddly enough, USB sticks prepared using unetbootin fail with Debian ISOs (boots but continually complains about not being able to find CD-ROM) but also works with CentOS based ISOs.
Every single Debian USB image I've tried to flash with dd has failed in the last few years. I have to boot up a windows virtual machine and use LinuxLive USB Creator to create one.
It's odd as the RaspberryPi debian image works perfectly fine.
That's odd. It should be fine, but here are some things to check:
- Make sure that none of the filesystems on the USB stick are mounted before you begin. Otherwise, the filesystem drivers might corrupt something.
- Use a larger block size that's a power of 2 (e.g. bs=4096k). The default is 512 bytes, which is too small. This should just speed things up, but using writes that are smaller than the actual flash erase blocks can cause a lot of extra erases, and maybe your flash stick breaks when you do that.
- Run 'sync' after using dd, and wait for disk activity to finish. dd doesn't flush to disk by default.
- Don't use an amd64 image on a 32-bit machine. Don't use ia64 on a 64-bit PC.
Thanks, I'll come back and read this next time I do it. The first thing I checked was the bit length, though it could be the file system type or the synchronized io
Because they can be used on CDs, used directly by VMs, and also imaged to USB/flash drives with tools like UNetBootin. It's just a convenient disk image format.
It might also be because that's the way debian-installer's written. I'd like to get it working with a copy of the CD filesystem on a drive - boot via UEFI
I doubt many people favor CDs over usb drives because they fear that somebody might rewrite the image on the media in the minutes between writing the image and actually sticking it in the other machine and using it.
In fact, it isn't even clear to me that CDs are favored in the first place. Everybody I know has been just using netinst from a usb stick for quite a while now... CDs are probably primarily used by people who want to give other people the install media, people who can't boot from USB on their computers, and people who still have a stack of CDs that they want to get rid of.
To be honest, the only reason I stopped using CDs is that for the past several years my computers haven't had optical drives (netbooks, now a chromebook). Otherwise I tend to be rather resistant to change.
"and people who still have a stack of CDs that they want to get rid of."
Ha! Yeah. I got a stack of 50 CDs several years ago, and the last 10 or so ... just didn't get used for anything. We eventually gave them to the younger teen for music school, 'cos the actual makes-money music industry still works with physical demo CDs. Some sort of proof-of-work thing, I think.
My last few computers have only included CD drives for the purpose of booting installers that are inconvenient to put on USB. USB drives, on the other hand, are quite universal.