The boot flag is from ancient times, where you would indicate an MBR partition record as bootable, so you could indicate where the boot loader resided.
On modern OS'es this is widely unused, as the MBR consists of a minimal stage loader which bootstraps either into its own partition or jumps to another area on the disk where the boot loader code is kept. (...
The MBR is 512 bytes, so a quick way to see if GRUB is there...
dd if=/dev/sda bs=512 count=1 | xxd
That dumps the MBR, I see "GRUB" in mine at byte 0x17F = 383.
dd if=/dev/sda bs=1 count=4 skip=383
When I do that, it prints 'GRUB' followed by the dd output.
You can wrap that in a bash for loop or something to go across more drives. if you don't want to ...
So, it sounds like you have not installed a boot loader (e.g. grub) on the disk. This means that although you have a valid OS on it, there is no way to boot it and so you can't use it.
You need to attach the HDD to a working computer (you can use a live CD), set up a chroot environment and install grub on it.
Mount the partition you will be using as / (I ...
There are several steps in the boot process (I'm describing a traditional PC BIOS):
The BIOS reads the first sector (512 bytes) of the boot disk.
The code in this first sector reads further data and code at a fixed location through the BIOS interface. This BIOS interface only exposes two hard disks: disk 0 is wherever the first sector was read from, and ...
The dd does not bypass the kernel disk caches when it writes to a device, so some part of data may be not written yet to the USB stick upon dd completion. If you unplug your USB stick at that moment, the content on the USB stick would be inconsistent. Thus, your system could even fail to boot from this USB stick.
Sync flushes any still-in-cache data to the ...
You have to Convert the ISO to UDRW format using:
hdiutil convert -format UDRW -o destination_file.img source_file.iso
for Further steps and reference click this link,
go with the steps: Create bootable USB stick from ISO in Mac OS X
Yes, you can accomplish this by adding a menu entry to the GRUB boot loader menu.
You can add a custom GRUB menu entry by editing /etc/grub.d/40_custom,
Example of custom menuentry:
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
I didn't convert the ISO to img, I just formatted a USB drive for FAT and used dd:
sudo diskutil unmountdisk /dev/disk1
sudo dd if=./debian.iso of=/dev/disk1 bs=1m
I tested this with Debian 9.
It's important to note that the appropriate /dev/disk# should be determined by using the following command on the macOS command line:
In the ...
That procedure has always worked for me. I tried using unetbootin with debian but for some reasons I was never able to make it work for Debian ISOs (strangely, it works without problems for other distros i've tried like Ubuntu, Finnix (both Debian based!) and CentOS).
But now, starting from Squeeze release, I found that the netinstall iso image works ...
I use both CloneZilla and Back In Time to do system and data back-ups respectively.
The advantage of CloneZilla over built-in tools like dd is that it uses its own partclone which creates very small images (it recognizes sparse files, can use a number of compression utilities, ...) and falls back to ddrescue which allows reading of damaged hard drives! (...
I'm working on an update to this question/answer.
This doesn't work without errors, but as I worked with @jiewmeng I uncovered that the goal was to use a USB to install both Windows and Ubuntu onto one hard drive, UEFI.
It has taken a while and I've found the solution but we need to clean the question and answer.
Maybe the original question can be answered ...
The terminology you're looking for is often called physical to virtual or virtual to physical. It's often shortened to P2V and V2P.
There's a tutorial on how to do this for VMware and Virtualbox over on the AskUbuntu site. The Q&A is titled: Migrate from a virtual machine (VM) to a physical system.
Migrating a Windows Guest
I found these instructions ...
Using gparted remove the existing partitions from your usb, and fix the msdos partition table (by going to the device menu and selecting "create partition Table"). Then, create a new partition fat32 by right clicking on the unallocated space and selecting new, making a primary FAT32 partition.
Next step create your bootable usb:
Use unetbootin : https://unetbootin.github.io/. Here is a tutorial for ubuntu but you can also use it for debian just change the image :http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-mac-osx
The first section in the "Compendium" (documentation) is the topic "How can I take this great Linux distribution for a spin?." It clearly states that the ISO is not a Hybrid boot, and that Rufus and other generic boot utilities will not work:
Deploying Nitrux to a PC
How to deploy Nitrux to your storage device.
Our ISO is a standard ISO-9660 ...
As the comment above states (from cnst), UDRW appears to be Apple/mac/OSX proprietary. I had to convert to "UDTO - DVD/CD-R master for export" to make the USB bootable on other machines. When dd is finished in this case OSX (Mavericks) complains that it cannot read the disk/USB in this format which kinda confirms it. Also, unetbootin for OSX does not work ...
Forget about rc.local.
You're using CentOS 7. You have systemd. /etc/rc.local is a double backwards compatibility mechanism in systemd, because it is a backwards compatibility mechanism for a mechanism that was itself a compatibility mechanism in System 5 rc. And as shown by the mess in the AskUbuntu question hyperlinked below, using /etc/rc.local can go ...
You should verify the .iso image : Steps to verify an ISO image
The available linux image come wiht the .iso extension and not .iso.part
Before unplugging your USB it is recommanded to run sync
There is an example:
dd if=linuxmint-18-xfce-64bit.iso of=/dev/sdb bs=4M status=progress oflag=sync
The syncis to make sure that all the writes are ...
BIOS machines boot disks.
UEFI machines boot the UEFI partition
So neither of those boot just any partition.
If you're looking to have a bootable ISO booting from a partition, you can add the ISO file to /etc/grub.d/40_custom and then grub will "boot" the ISO for you.
E.G. for gparted on my machine where /opt lives in hd2,gpt2
menuentry "GParted Live ISO"...
At first I thought it's a bug in grub2. Some BIOS seem to test if at least one partition is marked as bootable. After a long research I noticed that, because there was no way to boot from hdd or usb-stick at all.
That means even if magic bytes at the end of mbr are correct and boot-code in mbr is valid, BIOS will ignore that device and skip it in boot-...
Kept at it and figured it out, relatively straight forward from here, but not just a matter of setting up /etc/fstab, here is the rest:
not necessary but a good idea to clean things up
set up /etc/fstab - check with mount to ensure you are on the right filesystem type
echo "/dev/sda1 / ext4 defaults,errors=remount-ro 0 1" > /etc/...
Can't comment, but your "guide" worked wonders for making a Minimal Ubuntu 16 thumbdrive. The only things I changed were the debootstrap and I had to manually get networking working (networkd).
My debootstrap line was:
#> sudo debootstrap --components=main,contrib,nonfree --variant=minbase \
I managed to successfully use genisoimage (a debian fork of mkisofs).
loopback mount the iso
mount -o loop <image>.iso /mnt/iso
copy to secondary folder for r/w access
cp -R /mnt/iso/ /mnt/iso2
genisoimage -b <relative boot-img path> -no-emul-boot -boot-load-size 8 -iso-level 2 -udf -joliet -D -N -relaxed-filenames -o &...
I tried the Win7 solution described by Microsoft on a Windows machine:
and obtained the 0x80080005 error so went to Debian Stretch 9 to try to build the Windows 10 bootable USB using a e5.onthehub.com college/school ISO.
dd absolutely doesn't work for Windows 10. This only works for ...
The mkfs.fat command is redundant, since the dd command will overwrite the FAT file system with the pathtoiso.iso file (which contains an ISO9660 file system in itself). The point of the isohybrid command is to "enhance" the .iso file with a MBR partition table to make the result bootable from a USB Stick. See http://www.syslinux.org/wiki/index.php?title=...
Yes, it is possible to install linux from another linux install. One way is known as "poor man's install". You create a partition, copy the ISO contents there and use GRUB to boot and start the installer from that partition. There are several guides available online, e.g.:
Debian (see Installation media: Hard Disk)
Fedora (see Preparing for a Hard ...