Select Your Language

Infrastructure and Management

Cloud Computing

Storage

Runtimes

Integration and Automation

  • Comments
  • Some "dispappered" dm-? files under the /dev directory

    Posted on

    Recently I took over a few RHEL systems running with the native DM-multipath, which had been installed & configured by other persons.
    My doubts focus on the following questions:
    1. Why there would only a part of dm-? files from dm10~dm19 under the /dev directory
    2. Why all the mapper files do not point to their corresponding symbol link dm-? files
    Note: but all the complete dm-? in the system kernel can still be seen from the /proc/partitions.
    Despite these symptoms, all the systems running with the native DM-multipath can do work fine.

    # 
    # 
    # ls -ltr /dev/mapper
    total 0
    crw------- 1 root root  10, 60 Jun 22  2021 control
    brw-rw---- 1 root disk 253,  9 Jun 22  2021 vgroot-Lvswap
    brw-rw---- 1 root disk 253, 10 Jun 22  2021 3600c0ff0001582e1dc40b45101000000
    brw-rw---- 1 root disk 253, 17 Jun 22  2021 3600c0ff0001582e1bdaa115201000000
    brw-rw---- 1 root disk 253, 13 Jun 22  2021 3600c0ff0001582e1bc43b45101000000
    brw-rw---- 1 root disk 253, 16 Jun 22  2021 3600c0ff0001582e189aa115201000000
    brw-rw---- 1 root disk 253, 12 Jun 22  2021 3600c0ff0001582e16641b45101000000
    brw-rw---- 1 root disk 253, 15 Jun 22  2021 3600c0ff0001582e15bceba5101000000
    brw-rw---- 1 root disk 253, 14 Jun 22  2021 3600c0ff0001582e13bceba5101000000
    brw-rw---- 1 root disk 253, 11 Jun 22  2021 3600c0ff0001582e11141b45101000000
    brw-rw---- 1 root disk 253, 18 Jun 22  2021 3600c0ff0001581c1ca81625501000000
    brw-rw---- 1 root disk 253, 19 Jun 22  2021 3600c0ff0001581c1895b895901000000
    brw-rw---- 1 root disk 253, 20 Jun 22  2021 vgoms-lvoms
    brw-rw---- 1 root disk 253, 21 Jun 22  2021 vghes-lvhes
    brw-rw---- 1 root disk 253, 22 Jun 22  2021 vgdata-lvoadata
    brw-rw---- 1 root disk 253, 24 Jun 22  2021 vgdata-lvhnweb
    brw-rw---- 1 root disk 253, 23 Jun 22  2021 vgdata-lvdocdata
    brw-rw---- 1 root disk 253,  0 Jun 22  2021 vgroot-Lvroot
    brw-rw---- 1 root disk 253,  1 Jun 22  2021 vgroot-Lvhome
    brw-rw---- 1 root disk 253,  2 Jun 22  2021 vgroot-Lvvar
    brw-rw---- 1 root disk 253,  3 Jun 22  2021 vgroot-Lvtmp
    brw-rw---- 1 root disk 253,  4 Jun 22  2021 vgroot-Lvinstall
    brw-rw---- 1 root disk 253,  5 Jun 22  2021 vgroot-Lvusr
    brw-rw---- 1 root disk 253,  6 Jun 22  2021 vgroot-Lvopenv
    brw-rw---- 1 root disk 253,  7 Jun 22  2021 vgroot-Lvapp
    brw-rw---- 1 root disk 253,  8 Jun 22  2021 vgroot-Lvoracle
    brw-rw---- 1 root disk 253, 25 Nov 23 17:24 vgqdisk-lvqdisk
    # 
    # 
    # 
    # ls -l /dev/dm-*
    brw-rw---- 1 root root 253, 10 Jun 22  2021 /dev/dm-10
    brw-rw---- 1 root root 253, 11 Jun 22  2021 /dev/dm-11
    brw-rw---- 1 root root 253, 12 Jun 22  2021 /dev/dm-12
    brw-rw---- 1 root root 253, 13 Jun 22  2021 /dev/dm-13
    brw-rw---- 1 root root 253, 14 Jun 22  2021 /dev/dm-14
    brw-rw---- 1 root root 253, 15 Jun 22  2021 /dev/dm-15
    brw-rw---- 1 root root 253, 16 Jun 22  2021 /dev/dm-16
    brw-rw---- 1 root root 253, 17 Jun 22  2021 /dev/dm-17
    brw-rw---- 1 root root 253, 18 Jun 22  2021 /dev/dm-18
    brw-rw---- 1 root root 253, 19 Jun 22  2021 /dev/dm-19
    # 
    # 
    # 
    # cat /proc/partitions
    major minor  #blocks  name
    
     104     0  292935982 cciss/c0d0
     104     1     104391 cciss/c0d0p1
     104     2  292824787 cciss/c0d0p2
       8     0     976512 sda
       8    16   97656192 sdb
       8    32   97656192 sdc
       8    48   97656192 sdd
       8    64   97656192 sde
       8    80   97656192 sdf
       8    96   97656192 sdg
       8   112   97656192 sdh
       8   128  585937472 sdi
       8   144  989858240 sdj
       8   160     976512 sdk
       8   176   97656192 sdl
       8   192   97656192 sdm
       8   208   97656192 sdn
       8   224   97656192 sdo
       8   240   97656192 sdp
      65     0   97656192 sdq
      65    16   97656192 sdr
      65    32  585937472 sds
      65    48  989858240 sdt
     253     0   10485760 dm-0
     253     1    5242880 dm-1
     253     2    5242880 dm-2
     253     3    5242880 dm-3
     253     4   15728640 dm-4
     253     5   10485760 dm-5
     253     6   20971520 dm-6
     253     7   20971520 dm-7
     253     8   62914560 dm-8
     253     9   16777216 dm-9
     253    10     976512 dm-10
     253    11   97656192 dm-11
     253    12   97656192 dm-12
     253    13   97656192 dm-13
     253    14   97656192 dm-14
     253    15   97656192 dm-15
     253    16   97656192 dm-16
     253    17   97656192 dm-17
     253    18  585937472 dm-18
     253    19  989858240 dm-19
     253    20  989855744 dm-20
     253    21  585105408 dm-21
     253    22  209715200 dm-22
     253    23  209715200 dm-23
     253    24  209715200 dm-24
     253    25     974848 dm-25
    # 
    # 
    

    by

    points

    Responses

    Red Hat LinkedIn YouTube Facebook X, formerly Twitter

    Quick Links

    Help

    Site Info

    Related Sites

    © 2025 Red Hat