Specify the kernel dump output destination

Dynamic Link Manager (for Linux®) User Guide

Version
9.0.x
Audience
anonymous
Part Number
MK-92DLM113-64
ft:lastEdition
2025-11-06

To specify the kernel dump output destination, perform the following steps:

  • Create a partition.

  • Create a file system.

  • Edit the /etc/fstab file.

  • Edit the kdump function configuration file (/etc/kdump.conf).

  1. Execute the fdisk command to create a partition on the kernel dump output disk.

    Enter the values for the fdisk command as indicated by the underlined parts below.

    # fdisk /dev/sde
     
    The number of cylinders for this disk is set to 10240.
    There is nothing wrong with that, but this is larger than 1024,
    and could in certain setups cause problems with:
    1) software that runs at boot time (e.g., old versions of LILO)
    2) booting and partitioning software from other OSs
       (e.g., DOS FDISK, OS/2 FDISK)
     
    Command (m for help): p
     
    Disk /dev/sde: 10.7 GB, 10737418240 bytes
    64 heads, 32 sectors/track, 10240 cylinders
    Units = cylinders of 2048 * 512 = 1048576 bytes
     
       Device Boot      Start         End      Blocks   Id  System
     
    Command (m for help): n
    Command action
       e   extended
       p   primary partition (1-4)
    p
    Partition number (1-4): 1
    First cylinder (1-10240, default 1):   
    Using default value 1
    Last cylinder or +size or +sizeM or +sizeK (1-10240, default 10240):  
    Using default value 10240
     
    Command (m for help): p
     
    Disk /dev/sde: 10.7 GB, 10737418240 bytes
    64 heads, 32 sectors/track, 10240 cylinders
    Units = cylinders of 2048 * 512 = 1048576 bytes
     
       Device Boot      Start         End      Blocks   Id  System
    /dev/sde1               1       10240    10485744   83  Linux
     
    Command (m for help): w
    The partition table has been altered!
     
    Calling ioctl() to re-read partition table.
    Syncing disks.
  2. Execute the mkfs command to create a file system in the partition you created.

    If LABEL is used:

    Specify a volume label for the -L parameter. We recommend specifying a label name that indicates the label is used by the kdump function. If you specify a volume label for the kernel dump output destination, you will not need to correct any configuration file when the device configuration changes.

    In the following example, the volume label is set to kdump_disk:

    # mkfs -t ext3 -L kdump_disk /dev/sde1
    mke2fs 1.39 (29-May-2006)
    Filesystem label=kdump_disk
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    1310720 inodes, 2621436 blocks
    131071 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=2684354560
    80 block groups
    32768 blocks per group, 32768 fragments per group
    16384 inodes per group
    Superblock backups stored on blocks:
            32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
     
    Writing inode tables: done
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done
     
    This filesystem will be automatically checked every 24 mounts or
    180 days, whichever comes first.  Use tune2fs -c or -i to override.
    If UUID is used:

    After creating the file system, check the UUID that was set.

    # mkfs -t ext4 /dev/sde1 
    mke2fs 1.41.12 (17-May-2010)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    65536 inodes, 262094 blocks
    13104 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=268435456
    8 block groups
    32768 blocks per group, 32768 fragments per group
    8192 inodes per group
    Superblock backups stored on blocks:
            32768, 98304, 163840, 229376
    
    Writing inode tables: done
    Creating journal (4096 blocks): done
    Writing superblocks and filesystem accounting information: done
    
    This filesystem will be automatically checked every 30 mounts or
    180 days, whichever comes first.  Use tune2fs -c or -i to override.

    Execute the blkid command to check the UUID that was set.

    UUID="bf5d6d8d-d18b-45f8-8187-86837d895488" TYPE="ext4"
  3. Add the kernel dump output destination to the /etc/fstab file.

    If LABEL is used:

    For LABEL, specify the volume label you set in step 2.

    LABEL=kdump_disk /var/crash ext3 defaults 1 2
    If UUID is used:

    Specify the UUID you checked in step 2.

    UUID=bf5d6d8d-d18b-45f8-8187-86837d895488  /var/crash  ext4  defaults  1 2
  4. Add the kernel dump output destination to the kdump function configuration file (/etc/kdump.conf).

    If LABEL is used:

    For LABEL, specify the volume label you set in step 2.

    path hdlm
    ext3 LABEL=kdump_disk
    If UUID is used:

    Specify the UUID you checked in step 2.

    path hdlm
    ext4 UUID=bf5d6d8d-d18b-45f8-8187-86837d895488
  5. Add the timeout setting to the kdump function configuration file (/etc/kdump.conf).

    Timeout settings are not required for Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Oracle Linux 7, Oracle Linux 8 or Oracle Linux 9.

    disk_timeout 1