Why is “loop14” not listed in lsblk












1















Upon listing the blocks using lsblk, I found 14 look blocks listed, from loop 0 to loop 13.



me@alpha:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 87.9M 1 loop /snap/core/5662
loop1 7:1 0 140.7M 1 loop /snap/gnome-3-26-1604/74
loop2 7:2 0 3.7M 1 loop /snap/gnome-system-monitor/57
loop3 7:3 0 140.9M 1 loop /snap/gnome-3-26-1604/70
loop4 7:4 0 34.6M 1 loop /snap/gtk-common-themes/818
loop5 7:5 0 42.1M 1 loop /snap/gtk-common-themes/701
loop6 7:6 0 89.5M 1 loop /snap/core/6130
loop7 7:7 0 2.3M 1 loop /snap/gnome-calculator/238
loop8 7:8 0 130.2M 1 loop /snap/gnome-3-28-1804/4
loop9 7:9 0 14.5M 1 loop /snap/gnome-logs/45
loop10 7:10 0 13M 1 loop /snap/gnome-characters/124
loop11 7:11 0 53.7M 1 loop /snap/core18/536
loop12 7:12 0 13M 1 loop /snap/gnome-characters/139
loop13 7:13 0 2.3M 1 loop /snap/gnome-calculator/260
sda 8:0 0 113G 0 disk
├─sda1 8:1 0 512M 0 part /boot/efi
└─sda2 8:2 0 112.5G 0 part /


However, when I list using ls /dev and find blocks using grep 'loop', I found 15 blocks listed, with an extra loop14 shown.



me@alpha:~$ ls /dev | grep 'loop'
loop0
loop1
loop10
loop11
loop12
loop13
loop14
loop2
loop3
loop4
loop5
loop6
loop7
loop8
loop9
loop-control


Why loop14 is not listed from lsblk?









share





























    1















    Upon listing the blocks using lsblk, I found 14 look blocks listed, from loop 0 to loop 13.



    me@alpha:~$ lsblk
    NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
    loop0 7:0 0 87.9M 1 loop /snap/core/5662
    loop1 7:1 0 140.7M 1 loop /snap/gnome-3-26-1604/74
    loop2 7:2 0 3.7M 1 loop /snap/gnome-system-monitor/57
    loop3 7:3 0 140.9M 1 loop /snap/gnome-3-26-1604/70
    loop4 7:4 0 34.6M 1 loop /snap/gtk-common-themes/818
    loop5 7:5 0 42.1M 1 loop /snap/gtk-common-themes/701
    loop6 7:6 0 89.5M 1 loop /snap/core/6130
    loop7 7:7 0 2.3M 1 loop /snap/gnome-calculator/238
    loop8 7:8 0 130.2M 1 loop /snap/gnome-3-28-1804/4
    loop9 7:9 0 14.5M 1 loop /snap/gnome-logs/45
    loop10 7:10 0 13M 1 loop /snap/gnome-characters/124
    loop11 7:11 0 53.7M 1 loop /snap/core18/536
    loop12 7:12 0 13M 1 loop /snap/gnome-characters/139
    loop13 7:13 0 2.3M 1 loop /snap/gnome-calculator/260
    sda 8:0 0 113G 0 disk
    ├─sda1 8:1 0 512M 0 part /boot/efi
    └─sda2 8:2 0 112.5G 0 part /


    However, when I list using ls /dev and find blocks using grep 'loop', I found 15 blocks listed, with an extra loop14 shown.



    me@alpha:~$ ls /dev | grep 'loop'
    loop0
    loop1
    loop10
    loop11
    loop12
    loop13
    loop14
    loop2
    loop3
    loop4
    loop5
    loop6
    loop7
    loop8
    loop9
    loop-control


    Why loop14 is not listed from lsblk?









    share



























      1












      1








      1








      Upon listing the blocks using lsblk, I found 14 look blocks listed, from loop 0 to loop 13.



      me@alpha:~$ lsblk
      NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
      loop0 7:0 0 87.9M 1 loop /snap/core/5662
      loop1 7:1 0 140.7M 1 loop /snap/gnome-3-26-1604/74
      loop2 7:2 0 3.7M 1 loop /snap/gnome-system-monitor/57
      loop3 7:3 0 140.9M 1 loop /snap/gnome-3-26-1604/70
      loop4 7:4 0 34.6M 1 loop /snap/gtk-common-themes/818
      loop5 7:5 0 42.1M 1 loop /snap/gtk-common-themes/701
      loop6 7:6 0 89.5M 1 loop /snap/core/6130
      loop7 7:7 0 2.3M 1 loop /snap/gnome-calculator/238
      loop8 7:8 0 130.2M 1 loop /snap/gnome-3-28-1804/4
      loop9 7:9 0 14.5M 1 loop /snap/gnome-logs/45
      loop10 7:10 0 13M 1 loop /snap/gnome-characters/124
      loop11 7:11 0 53.7M 1 loop /snap/core18/536
      loop12 7:12 0 13M 1 loop /snap/gnome-characters/139
      loop13 7:13 0 2.3M 1 loop /snap/gnome-calculator/260
      sda 8:0 0 113G 0 disk
      ├─sda1 8:1 0 512M 0 part /boot/efi
      └─sda2 8:2 0 112.5G 0 part /


      However, when I list using ls /dev and find blocks using grep 'loop', I found 15 blocks listed, with an extra loop14 shown.



      me@alpha:~$ ls /dev | grep 'loop'
      loop0
      loop1
      loop10
      loop11
      loop12
      loop13
      loop14
      loop2
      loop3
      loop4
      loop5
      loop6
      loop7
      loop8
      loop9
      loop-control


      Why loop14 is not listed from lsblk?









      share
















      Upon listing the blocks using lsblk, I found 14 look blocks listed, from loop 0 to loop 13.



      me@alpha:~$ lsblk
      NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
      loop0 7:0 0 87.9M 1 loop /snap/core/5662
      loop1 7:1 0 140.7M 1 loop /snap/gnome-3-26-1604/74
      loop2 7:2 0 3.7M 1 loop /snap/gnome-system-monitor/57
      loop3 7:3 0 140.9M 1 loop /snap/gnome-3-26-1604/70
      loop4 7:4 0 34.6M 1 loop /snap/gtk-common-themes/818
      loop5 7:5 0 42.1M 1 loop /snap/gtk-common-themes/701
      loop6 7:6 0 89.5M 1 loop /snap/core/6130
      loop7 7:7 0 2.3M 1 loop /snap/gnome-calculator/238
      loop8 7:8 0 130.2M 1 loop /snap/gnome-3-28-1804/4
      loop9 7:9 0 14.5M 1 loop /snap/gnome-logs/45
      loop10 7:10 0 13M 1 loop /snap/gnome-characters/124
      loop11 7:11 0 53.7M 1 loop /snap/core18/536
      loop12 7:12 0 13M 1 loop /snap/gnome-characters/139
      loop13 7:13 0 2.3M 1 loop /snap/gnome-calculator/260
      sda 8:0 0 113G 0 disk
      ├─sda1 8:1 0 512M 0 part /boot/efi
      └─sda2 8:2 0 112.5G 0 part /


      However, when I list using ls /dev and find blocks using grep 'loop', I found 15 blocks listed, with an extra loop14 shown.



      me@alpha:~$ ls /dev | grep 'loop'
      loop0
      loop1
      loop10
      loop11
      loop12
      loop13
      loop14
      loop2
      loop3
      loop4
      loop5
      loop6
      loop7
      loop8
      loop9
      loop-control


      Why loop14 is not listed from lsblk?







      devices lsblk





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      edited 1 hour ago









      thephoenix01

      402414




      402414










      asked 2 hours ago









      AliceAlice

      193110




      193110






















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          lsblk lists loop devices with a backing file. In your case, loop devices 0-13 have backing files, and show up.



          losetup --find, used to find the next available loop device, automatically creates a new loop device if all existing loop devices are in use (if run as root). So some process might have run losetup --find as root to look for an available loop device, and probably didn't use it.



          Example:



          I have seven loop devices, all backed:



          $ sudo losetup --list --all         
          NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
          /dev/loop1 0 0 1 1 /var/lib/snapd/snaps/core_5897.snap
          /dev/loop6 0 0 0 0 /tmp/foo
          /dev/loop4 0 0 0 0 /tmp/foo
          /dev/loop2 0 0 1 1 /var/lib/snapd/snaps/core_6130.snap
          /dev/loop0 0 0 1 1 /var/lib/snapd/snaps/vuze-vs_3.snap
          /dev/loop7 0 0 0 0 /tmp/foo
          /dev/loop5 0 0 0 0 /tmp/foo
          /dev/loop3 0 0 1 1 /var/lib/snapd/snaps/core_6034.snap
          $ ls /dev/loop*
          /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop-control
          /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7


          I ask losetup for the next available loop device as root:



          $ sudo losetup --find       
          /dev/loop8


          And losetup has created this for me:



          $ ls /dev/loop*             
          /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop8
          /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7 /dev/loop-control


          But it's not in lsblk:



          $ lsblk              
          NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
          loop1 7:1 0 88.2M 1 loop /snap/core/5897
          loop6 7:6 0 1M 0 loop
          loop4 7:4 0 1M 0 loop
          sr0 11:0 1 1024M 0 rom
          loop2 7:2 0 89.5M 1 loop /snap/core/6130
          loop0 7:0 0 280.2M 1 loop /snap/vuze-vs/3
          loop7 7:7 0 1M 0 loop
          sda 8:0 0 41G 0 disk
          └─sda1 8:1 0 41G 0 part /
          loop5 7:5 0 1M 0 loop
          loop3 7:3 0 89.5M 1 loop /snap/core/6034


          Because it's not backed by anything usable as a block device.






          share|improve this answer























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            1 Answer
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            1 Answer
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            active

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            active

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            2














            lsblk lists loop devices with a backing file. In your case, loop devices 0-13 have backing files, and show up.



            losetup --find, used to find the next available loop device, automatically creates a new loop device if all existing loop devices are in use (if run as root). So some process might have run losetup --find as root to look for an available loop device, and probably didn't use it.



            Example:



            I have seven loop devices, all backed:



            $ sudo losetup --list --all         
            NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
            /dev/loop1 0 0 1 1 /var/lib/snapd/snaps/core_5897.snap
            /dev/loop6 0 0 0 0 /tmp/foo
            /dev/loop4 0 0 0 0 /tmp/foo
            /dev/loop2 0 0 1 1 /var/lib/snapd/snaps/core_6130.snap
            /dev/loop0 0 0 1 1 /var/lib/snapd/snaps/vuze-vs_3.snap
            /dev/loop7 0 0 0 0 /tmp/foo
            /dev/loop5 0 0 0 0 /tmp/foo
            /dev/loop3 0 0 1 1 /var/lib/snapd/snaps/core_6034.snap
            $ ls /dev/loop*
            /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop-control
            /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7


            I ask losetup for the next available loop device as root:



            $ sudo losetup --find       
            /dev/loop8


            And losetup has created this for me:



            $ ls /dev/loop*             
            /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop8
            /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7 /dev/loop-control


            But it's not in lsblk:



            $ lsblk              
            NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
            loop1 7:1 0 88.2M 1 loop /snap/core/5897
            loop6 7:6 0 1M 0 loop
            loop4 7:4 0 1M 0 loop
            sr0 11:0 1 1024M 0 rom
            loop2 7:2 0 89.5M 1 loop /snap/core/6130
            loop0 7:0 0 280.2M 1 loop /snap/vuze-vs/3
            loop7 7:7 0 1M 0 loop
            sda 8:0 0 41G 0 disk
            └─sda1 8:1 0 41G 0 part /
            loop5 7:5 0 1M 0 loop
            loop3 7:3 0 89.5M 1 loop /snap/core/6034


            Because it's not backed by anything usable as a block device.






            share|improve this answer




























              2














              lsblk lists loop devices with a backing file. In your case, loop devices 0-13 have backing files, and show up.



              losetup --find, used to find the next available loop device, automatically creates a new loop device if all existing loop devices are in use (if run as root). So some process might have run losetup --find as root to look for an available loop device, and probably didn't use it.



              Example:



              I have seven loop devices, all backed:



              $ sudo losetup --list --all         
              NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
              /dev/loop1 0 0 1 1 /var/lib/snapd/snaps/core_5897.snap
              /dev/loop6 0 0 0 0 /tmp/foo
              /dev/loop4 0 0 0 0 /tmp/foo
              /dev/loop2 0 0 1 1 /var/lib/snapd/snaps/core_6130.snap
              /dev/loop0 0 0 1 1 /var/lib/snapd/snaps/vuze-vs_3.snap
              /dev/loop7 0 0 0 0 /tmp/foo
              /dev/loop5 0 0 0 0 /tmp/foo
              /dev/loop3 0 0 1 1 /var/lib/snapd/snaps/core_6034.snap
              $ ls /dev/loop*
              /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop-control
              /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7


              I ask losetup for the next available loop device as root:



              $ sudo losetup --find       
              /dev/loop8


              And losetup has created this for me:



              $ ls /dev/loop*             
              /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop8
              /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7 /dev/loop-control


              But it's not in lsblk:



              $ lsblk              
              NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
              loop1 7:1 0 88.2M 1 loop /snap/core/5897
              loop6 7:6 0 1M 0 loop
              loop4 7:4 0 1M 0 loop
              sr0 11:0 1 1024M 0 rom
              loop2 7:2 0 89.5M 1 loop /snap/core/6130
              loop0 7:0 0 280.2M 1 loop /snap/vuze-vs/3
              loop7 7:7 0 1M 0 loop
              sda 8:0 0 41G 0 disk
              └─sda1 8:1 0 41G 0 part /
              loop5 7:5 0 1M 0 loop
              loop3 7:3 0 89.5M 1 loop /snap/core/6034


              Because it's not backed by anything usable as a block device.






              share|improve this answer


























                2












                2








                2







                lsblk lists loop devices with a backing file. In your case, loop devices 0-13 have backing files, and show up.



                losetup --find, used to find the next available loop device, automatically creates a new loop device if all existing loop devices are in use (if run as root). So some process might have run losetup --find as root to look for an available loop device, and probably didn't use it.



                Example:



                I have seven loop devices, all backed:



                $ sudo losetup --list --all         
                NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
                /dev/loop1 0 0 1 1 /var/lib/snapd/snaps/core_5897.snap
                /dev/loop6 0 0 0 0 /tmp/foo
                /dev/loop4 0 0 0 0 /tmp/foo
                /dev/loop2 0 0 1 1 /var/lib/snapd/snaps/core_6130.snap
                /dev/loop0 0 0 1 1 /var/lib/snapd/snaps/vuze-vs_3.snap
                /dev/loop7 0 0 0 0 /tmp/foo
                /dev/loop5 0 0 0 0 /tmp/foo
                /dev/loop3 0 0 1 1 /var/lib/snapd/snaps/core_6034.snap
                $ ls /dev/loop*
                /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop-control
                /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7


                I ask losetup for the next available loop device as root:



                $ sudo losetup --find       
                /dev/loop8


                And losetup has created this for me:



                $ ls /dev/loop*             
                /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop8
                /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7 /dev/loop-control


                But it's not in lsblk:



                $ lsblk              
                NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
                loop1 7:1 0 88.2M 1 loop /snap/core/5897
                loop6 7:6 0 1M 0 loop
                loop4 7:4 0 1M 0 loop
                sr0 11:0 1 1024M 0 rom
                loop2 7:2 0 89.5M 1 loop /snap/core/6130
                loop0 7:0 0 280.2M 1 loop /snap/vuze-vs/3
                loop7 7:7 0 1M 0 loop
                sda 8:0 0 41G 0 disk
                └─sda1 8:1 0 41G 0 part /
                loop5 7:5 0 1M 0 loop
                loop3 7:3 0 89.5M 1 loop /snap/core/6034


                Because it's not backed by anything usable as a block device.






                share|improve this answer













                lsblk lists loop devices with a backing file. In your case, loop devices 0-13 have backing files, and show up.



                losetup --find, used to find the next available loop device, automatically creates a new loop device if all existing loop devices are in use (if run as root). So some process might have run losetup --find as root to look for an available loop device, and probably didn't use it.



                Example:



                I have seven loop devices, all backed:



                $ sudo losetup --list --all         
                NAME SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE
                /dev/loop1 0 0 1 1 /var/lib/snapd/snaps/core_5897.snap
                /dev/loop6 0 0 0 0 /tmp/foo
                /dev/loop4 0 0 0 0 /tmp/foo
                /dev/loop2 0 0 1 1 /var/lib/snapd/snaps/core_6130.snap
                /dev/loop0 0 0 1 1 /var/lib/snapd/snaps/vuze-vs_3.snap
                /dev/loop7 0 0 0 0 /tmp/foo
                /dev/loop5 0 0 0 0 /tmp/foo
                /dev/loop3 0 0 1 1 /var/lib/snapd/snaps/core_6034.snap
                $ ls /dev/loop*
                /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop-control
                /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7


                I ask losetup for the next available loop device as root:



                $ sudo losetup --find       
                /dev/loop8


                And losetup has created this for me:



                $ ls /dev/loop*             
                /dev/loop0 /dev/loop2 /dev/loop4 /dev/loop6 /dev/loop8
                /dev/loop1 /dev/loop3 /dev/loop5 /dev/loop7 /dev/loop-control


                But it's not in lsblk:



                $ lsblk              
                NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
                loop1 7:1 0 88.2M 1 loop /snap/core/5897
                loop6 7:6 0 1M 0 loop
                loop4 7:4 0 1M 0 loop
                sr0 11:0 1 1024M 0 rom
                loop2 7:2 0 89.5M 1 loop /snap/core/6130
                loop0 7:0 0 280.2M 1 loop /snap/vuze-vs/3
                loop7 7:7 0 1M 0 loop
                sda 8:0 0 41G 0 disk
                └─sda1 8:1 0 41G 0 part /
                loop5 7:5 0 1M 0 loop
                loop3 7:3 0 89.5M 1 loop /snap/core/6034


                Because it's not backed by anything usable as a block device.







                share|improve this answer












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                share|improve this answer










                answered 2 hours ago









                OlorinOlorin

                1,961719




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