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 2 hours ago









      AliceAlice

      426110




      426110






















          1 Answer
          1






          active

          oldest

          votes


















          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 B - 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 B 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


























          • @Mehrdad 512 B. Fixed. Thanks

            – Sergiy Kolodyazhnyy
            29 mins ago











          Your Answer








          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "89"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faskubuntu.com%2fquestions%2f1122619%2fdoes-rm-fr-remove-the-boot-loader%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          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 B - 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 B 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


























          • @Mehrdad 512 B. Fixed. Thanks

            – Sergiy Kolodyazhnyy
            29 mins ago
















          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 B - 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 B 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


























          • @Mehrdad 512 B. Fixed. Thanks

            – Sergiy Kolodyazhnyy
            29 mins ago














          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 B - 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 B 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 B - 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 B 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 29 mins ago

























          answered 2 hours ago









          Sergiy KolodyazhnyySergiy Kolodyazhnyy

          73.4k9153318




          73.4k9153318













          • @Mehrdad 512 B. Fixed. Thanks

            – Sergiy Kolodyazhnyy
            29 mins ago



















          • @Mehrdad 512 B. Fixed. Thanks

            – Sergiy Kolodyazhnyy
            29 mins ago

















          @Mehrdad 512 B. Fixed. Thanks

          – Sergiy Kolodyazhnyy
          29 mins ago





          @Mehrdad 512 B. Fixed. Thanks

          – Sergiy Kolodyazhnyy
          29 mins ago


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Ask Ubuntu!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faskubuntu.com%2fquestions%2f1122619%2fdoes-rm-fr-remove-the-boot-loader%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          數位音樂下載

          When can things happen in Etherscan, such as the picture below?

          格利澤436b