Does 'rm -fr` remove the boot loader?












1















I learned that the boot loader is permanently stored in the machine's ROM and today’s PCs is constructed with flash memory technology so it could be altered under special circumstances.



Is rm -rf / is the special circumstance?



Does rm -rf remove the boot loader?










share|improve this question



























    1















    I learned that the boot loader is permanently stored in the machine's ROM and today’s PCs is constructed with flash memory technology so it could be altered under special circumstances.



    Is rm -rf / is the special circumstance?



    Does rm -rf remove the boot loader?










    share|improve this question

























      1












      1








      1








      I learned that the boot loader is permanently stored in the machine's ROM and today’s PCs is constructed with flash memory technology so it could be altered under special circumstances.



      Is rm -rf / is the special circumstance?



      Does rm -rf remove the boot loader?










      share|improve this question














      I learned that the boot loader is permanently stored in the machine's ROM and today’s PCs is constructed with flash memory technology so it could be altered under special circumstances.



      Is rm -rf / is the special circumstance?



      Does rm -rf remove the boot loader?







      boot






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked 1 hour ago









      AliceAlice

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      426110






















          1 Answer
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          TL;DR: rm -rf / doesn't remove bootloader itself, but everything that bootloader needs (and everything OS needs to function).




          boot loader is permanently stored in the machine's ROM




          Not quite. On most modern systems, bootloader can be either on Master Boot Record part of the disk - the first 512 MB - or it can be on separate device (see also). And to quote Wikipedia about linux kernel image:




          ...limitations on some i386 systems meant only the first 1024 cylinders of the hard disk were addressable.



          To overcome this, Linux distributors encouraged users to create a partition at the beginning of their drives specifically for storing bootloader and kernel related files.




          Embedded systems, such as Raspberry Pi, may in fact have a bootloader (or first stage bootloader) in ROM.





          rm -rf / like any other command is loaded in memory and executed from there, so it removes recursively everything in / directory (/ filesystem), including its own original file /bin/rm. It generally knows nothing about MBR partition and operates only on all files/directories that can be found under /.



          In other words, the first 512 MB of disk that have the bootloader itself aren't removed, but /boot directory is removed, and that does contain configuration files for bootloader (typically GRUB) and temporary filesystem initrd.img which is loaded before the main / filesystem. If you look at the Grub rescue article on linux.com, you'll see that even though bootloader itself might be working, it has to know the disk on which root filesystem is located, where kernel image vmlinuz is located, and initrd. That is, the example they give in grub's shell is



          grub> set root=(hd0,1)
          grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
          grub> initrd /boot/initrd.img-3.13.0-29-generic
          grub> boot


          where (hd0,1) identifies disk and partition with root filesystem.



          Even though bootloader itself is not removed, when /boot alone is removed that does lead to problems. In case of rm -rf / you are removing everything from filesystem, including init - the very first process, the kernel






          share|improve this answer

























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            TL;DR: rm -rf / doesn't remove bootloader itself, but everything that bootloader needs (and everything OS needs to function).




            boot loader is permanently stored in the machine's ROM




            Not quite. On most modern systems, bootloader can be either on Master Boot Record part of the disk - the first 512 MB - or it can be on separate device (see also). And to quote Wikipedia about linux kernel image:




            ...limitations on some i386 systems meant only the first 1024 cylinders of the hard disk were addressable.



            To overcome this, Linux distributors encouraged users to create a partition at the beginning of their drives specifically for storing bootloader and kernel related files.




            Embedded systems, such as Raspberry Pi, may in fact have a bootloader (or first stage bootloader) in ROM.





            rm -rf / like any other command is loaded in memory and executed from there, so it removes recursively everything in / directory (/ filesystem), including its own original file /bin/rm. It generally knows nothing about MBR partition and operates only on all files/directories that can be found under /.



            In other words, the first 512 MB of disk that have the bootloader itself aren't removed, but /boot directory is removed, and that does contain configuration files for bootloader (typically GRUB) and temporary filesystem initrd.img which is loaded before the main / filesystem. If you look at the Grub rescue article on linux.com, you'll see that even though bootloader itself might be working, it has to know the disk on which root filesystem is located, where kernel image vmlinuz is located, and initrd. That is, the example they give in grub's shell is



            grub> set root=(hd0,1)
            grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
            grub> initrd /boot/initrd.img-3.13.0-29-generic
            grub> boot


            where (hd0,1) identifies disk and partition with root filesystem.



            Even though bootloader itself is not removed, when /boot alone is removed that does lead to problems. In case of rm -rf / you are removing everything from filesystem, including init - the very first process, the kernel






            share|improve this answer






























              2














              TL;DR: rm -rf / doesn't remove bootloader itself, but everything that bootloader needs (and everything OS needs to function).




              boot loader is permanently stored in the machine's ROM




              Not quite. On most modern systems, bootloader can be either on Master Boot Record part of the disk - the first 512 MB - or it can be on separate device (see also). And to quote Wikipedia about linux kernel image:




              ...limitations on some i386 systems meant only the first 1024 cylinders of the hard disk were addressable.



              To overcome this, Linux distributors encouraged users to create a partition at the beginning of their drives specifically for storing bootloader and kernel related files.




              Embedded systems, such as Raspberry Pi, may in fact have a bootloader (or first stage bootloader) in ROM.





              rm -rf / like any other command is loaded in memory and executed from there, so it removes recursively everything in / directory (/ filesystem), including its own original file /bin/rm. It generally knows nothing about MBR partition and operates only on all files/directories that can be found under /.



              In other words, the first 512 MB of disk that have the bootloader itself aren't removed, but /boot directory is removed, and that does contain configuration files for bootloader (typically GRUB) and temporary filesystem initrd.img which is loaded before the main / filesystem. If you look at the Grub rescue article on linux.com, you'll see that even though bootloader itself might be working, it has to know the disk on which root filesystem is located, where kernel image vmlinuz is located, and initrd. That is, the example they give in grub's shell is



              grub> set root=(hd0,1)
              grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
              grub> initrd /boot/initrd.img-3.13.0-29-generic
              grub> boot


              where (hd0,1) identifies disk and partition with root filesystem.



              Even though bootloader itself is not removed, when /boot alone is removed that does lead to problems. In case of rm -rf / you are removing everything from filesystem, including init - the very first process, the kernel






              share|improve this answer




























                2












                2








                2







                TL;DR: rm -rf / doesn't remove bootloader itself, but everything that bootloader needs (and everything OS needs to function).




                boot loader is permanently stored in the machine's ROM




                Not quite. On most modern systems, bootloader can be either on Master Boot Record part of the disk - the first 512 MB - or it can be on separate device (see also). And to quote Wikipedia about linux kernel image:




                ...limitations on some i386 systems meant only the first 1024 cylinders of the hard disk were addressable.



                To overcome this, Linux distributors encouraged users to create a partition at the beginning of their drives specifically for storing bootloader and kernel related files.




                Embedded systems, such as Raspberry Pi, may in fact have a bootloader (or first stage bootloader) in ROM.





                rm -rf / like any other command is loaded in memory and executed from there, so it removes recursively everything in / directory (/ filesystem), including its own original file /bin/rm. It generally knows nothing about MBR partition and operates only on all files/directories that can be found under /.



                In other words, the first 512 MB of disk that have the bootloader itself aren't removed, but /boot directory is removed, and that does contain configuration files for bootloader (typically GRUB) and temporary filesystem initrd.img which is loaded before the main / filesystem. If you look at the Grub rescue article on linux.com, you'll see that even though bootloader itself might be working, it has to know the disk on which root filesystem is located, where kernel image vmlinuz is located, and initrd. That is, the example they give in grub's shell is



                grub> set root=(hd0,1)
                grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
                grub> initrd /boot/initrd.img-3.13.0-29-generic
                grub> boot


                where (hd0,1) identifies disk and partition with root filesystem.



                Even though bootloader itself is not removed, when /boot alone is removed that does lead to problems. In case of rm -rf / you are removing everything from filesystem, including init - the very first process, the kernel






                share|improve this answer















                TL;DR: rm -rf / doesn't remove bootloader itself, but everything that bootloader needs (and everything OS needs to function).




                boot loader is permanently stored in the machine's ROM




                Not quite. On most modern systems, bootloader can be either on Master Boot Record part of the disk - the first 512 MB - or it can be on separate device (see also). And to quote Wikipedia about linux kernel image:




                ...limitations on some i386 systems meant only the first 1024 cylinders of the hard disk were addressable.



                To overcome this, Linux distributors encouraged users to create a partition at the beginning of their drives specifically for storing bootloader and kernel related files.




                Embedded systems, such as Raspberry Pi, may in fact have a bootloader (or first stage bootloader) in ROM.





                rm -rf / like any other command is loaded in memory and executed from there, so it removes recursively everything in / directory (/ filesystem), including its own original file /bin/rm. It generally knows nothing about MBR partition and operates only on all files/directories that can be found under /.



                In other words, the first 512 MB of disk that have the bootloader itself aren't removed, but /boot directory is removed, and that does contain configuration files for bootloader (typically GRUB) and temporary filesystem initrd.img which is loaded before the main / filesystem. If you look at the Grub rescue article on linux.com, you'll see that even though bootloader itself might be working, it has to know the disk on which root filesystem is located, where kernel image vmlinuz is located, and initrd. That is, the example they give in grub's shell is



                grub> set root=(hd0,1)
                grub> linux /boot/vmlinuz-3.13.0-29-generic root=/dev/sda1
                grub> initrd /boot/initrd.img-3.13.0-29-generic
                grub> boot


                where (hd0,1) identifies disk and partition with root filesystem.



                Even though bootloader itself is not removed, when /boot alone is removed that does lead to problems. In case of rm -rf / you are removing everything from filesystem, including init - the very first process, the kernel







                share|improve this answer














                share|improve this answer



                share|improve this answer








                edited 56 mins ago

























                answered 1 hour ago









                Sergiy KolodyazhnyySergiy Kolodyazhnyy

                73.4k9153318




                73.4k9153318






























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