Print this page
NEX-9586 remove nodename from the default savecore directory path
Reviewed by: Dan Fields <dan.fields@nexenta.com>
Reviewed by: Yuri Pankov <yuri.pankov@nexenta.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>


  42        to the file system named vmdump.X. If compression is disabled, it
  43        instead writes two files named unix.X and vmcore.X. In the uncompressed
  44        case, both data files form the saved crash dump. In both cases X is an
  45        integer identifying the dump.
  46 
  47 
  48        For systems with a UFS root file system, the default dump device is
  49        configured to be an appropriate swap partition. Swap partitions are
  50        disk partitions reserved as virtual memory backing store for the
  51        operating system. Thus, no permanent information resides in swap to be
  52        overwritten by the dump. See swap(1M). For systems with a ZFS root file
  53        system, dedicated ZFS volumes are used for swap and dump areas. For
  54        further information about setting up a dump area with ZFS,  see the ZFS
  55        Administration Guide. To view the current dump  configuration, use the
  56        dumpadm command with no arguments:
  57 
  58          example# dumpadm
  59 
  60                Dump content: kernel pages
  61                 Dump device: /dev/dsk/c0t0d0s1 (swap)
  62          Savecore directory: /var/crash/saturn
  63            Savecore enabled: yes
  64             Save compressed: on
  65 
  66 
  67 
  68 
  69        When no options are specified, dumpadm prints the current crash dump
  70        configuration. The example shows the set of default values: the dump
  71        content is set to kernel memory pages only, the dump device is a swap
  72        disk partition, the directory for savecore files is set to
  73        /var/crash/hostname, savecore is set to run automatically on reboot,
  74        and compression is turned on.
  75 
  76 
  77        When one or more options are specified, dumpadm verifies that your
  78        changes are valid, and if so, reconfigures the crash dump parameters
  79        and displays the resulting configuration. You must be root to view or
  80        change dump parameters.
  81 
  82 OPTIONS
  83        The following options are supported:
  84 
  85        -c content-type
  86 
  87            Modify the dump configuration so that the crash dump consists of
  88            the specified dump content. The content should be one of the
  89            following:
  90 
  91            kernel
  92 
  93                Kernel memory pages only.
  94 


 189            dump device is a swap partition, the dump data will be overwritten
 190            as the system begins to swap. If savecore is not executed shortly
 191            after boot, crash dump retrieval may not be possible.
 192 
 193 
 194        -r root-dir
 195 
 196            Specify an alternate root directory relative to which dumpadm
 197            should create files. If no -r argument is specified, the default
 198            root directory / is used.
 199 
 200 
 201        -s savecore-dir
 202 
 203            Modify the dump configuration to use the specified directory to
 204            save files written by savecore. The directory should be an absolute
 205            path and exist on the system. If upon reboot the directory does not
 206            exist, it will be created prior to the execution of savecore. See
 207            the NOTES section below for a discussion of security issues
 208            relating to access to the savecore directory.  The default savecore
 209            directory is /var/crash/hostname where hostname is the output of
 210            the -n option to the uname(1) command.
 211 
 212 
 213        -u
 214 
 215            Forcibly update the kernel dump configuration based on the contents
 216            of /etc/dumpadm.conf. Normally this option is used only on reboot
 217            when starting svc:/system/dumpadm:default, when the dumpadm
 218            settings from the previous boot must be restored. Your dump
 219            configuration is saved in the configuration file for this purpose.
 220            If the configuration file is missing or contains invalid values for
 221            any dump properties, the default values are substituted. Following
 222            the update, the configuration file is resynchronized with the
 223            kernel dump configuration.
 224 
 225 
 226        -y
 227 
 228            Modify the dump configuration to automatically run savecore on
 229            reboot.  This is the default for this dump setting.
 230 
 231 
 232        -z on | off
 233 
 234            Turns crash dump compression on or off.
 235 
 236 
 237 EXAMPLES
 238        Example 1 Reconfiguring The Dump Device To A Dedicated Dump Device:
 239 
 240 
 241        The following command reconfigures the dump device to a dedicated dump
 242        device:
 243 
 244 
 245          example# dumpadm -d /dev/dsk/c0t2d0s2
 246 
 247                     Dump content: kernel pages
 248                      Dump device: /dev/dsk/c0t2d0s2 (dedicated)
 249               Savecore directory: /var/crash/saturn
 250                 Savecore enabled: yes
 251                  Save compressed: on
 252 
 253 
 254 
 255 EXIT STATUS
 256        The following exit values are returned:
 257 
 258        0
 259 
 260            Dump configuration is valid and the specified modifications, if
 261            any, were made successfully.
 262 
 263 
 264        1
 265 
 266            A fatal error occurred in either obtaining or modifying the dump
 267            configuration.
 268 
 269 


 339    Minimum Free Space
 340        If the dumpadm -m option is used to create a minfree file based on a
 341        percentage of the total size of the file system containing the savecore
 342        directory, this value is not automatically recomputed if the file
 343        system subsequently changes size.  In this case, the administrator must
 344        re-execute dumpadm -m to recompute the minfree value. If no such file
 345        exists in the savecore directory, savecore will default to a free space
 346        threshold of one megabyte. If no free space threshold is desired, a
 347        minfree file containing size 0 can be created.
 348 
 349    Security Issues
 350        If, upon reboot, the specified savecore directory is not present, it
 351        will be created prior to the execution of savecore with permissions
 352        0700 (read, write, execute by owner only) and owner root. It is
 353        recommended that alternate savecore directories also be created with
 354        similar permissions, as the operating system crash dump files
 355        themselves may contain secure information.
 356 
 357 
 358 
 359                                  April 9, 2015                     DUMPADM(1M)


  42        to the file system named vmdump.X. If compression is disabled, it
  43        instead writes two files named unix.X and vmcore.X. In the uncompressed
  44        case, both data files form the saved crash dump. In both cases X is an
  45        integer identifying the dump.
  46 
  47 
  48        For systems with a UFS root file system, the default dump device is
  49        configured to be an appropriate swap partition. Swap partitions are
  50        disk partitions reserved as virtual memory backing store for the
  51        operating system. Thus, no permanent information resides in swap to be
  52        overwritten by the dump. See swap(1M). For systems with a ZFS root file
  53        system, dedicated ZFS volumes are used for swap and dump areas. For
  54        further information about setting up a dump area with ZFS,  see the ZFS
  55        Administration Guide. To view the current dump  configuration, use the
  56        dumpadm command with no arguments:
  57 
  58          example# dumpadm
  59 
  60                Dump content: kernel pages
  61                 Dump device: /dev/dsk/c0t0d0s1 (swap)
  62          Savecore directory: /var/crash
  63            Savecore enabled: yes
  64             Save compressed: on
  65 
  66 
  67 
  68 
  69        When no options are specified, dumpadm prints the current crash dump
  70        configuration. The example shows the set of default values: the dump
  71        content is set to kernel memory pages only, the dump device is a swap
  72        disk partition, the directory for savecore files is set to /var/crash,
  73        savecore is set to run automatically on reboot, and compression is
  74        turned on.
  75 
  76 
  77        When one or more options are specified, dumpadm verifies that your
  78        changes are valid, and if so, reconfigures the crash dump parameters
  79        and displays the resulting configuration. You must be root to view or
  80        change dump parameters.
  81 
  82 OPTIONS
  83        The following options are supported:
  84 
  85        -c content-type
  86 
  87            Modify the dump configuration so that the crash dump consists of
  88            the specified dump content. The content should be one of the
  89            following:
  90 
  91            kernel
  92 
  93                Kernel memory pages only.
  94 


 189            dump device is a swap partition, the dump data will be overwritten
 190            as the system begins to swap. If savecore is not executed shortly
 191            after boot, crash dump retrieval may not be possible.
 192 
 193 
 194        -r root-dir
 195 
 196            Specify an alternate root directory relative to which dumpadm
 197            should create files. If no -r argument is specified, the default
 198            root directory / is used.
 199 
 200 
 201        -s savecore-dir
 202 
 203            Modify the dump configuration to use the specified directory to
 204            save files written by savecore. The directory should be an absolute
 205            path and exist on the system. If upon reboot the directory does not
 206            exist, it will be created prior to the execution of savecore. See
 207            the NOTES section below for a discussion of security issues
 208            relating to access to the savecore directory.  The default savecore
 209            directory is /var/crash.

 210 
 211 
 212        -u
 213 
 214            Forcibly update the kernel dump configuration based on the contents
 215            of /etc/dumpadm.conf. Normally this option is used only on reboot
 216            when starting svc:/system/dumpadm:default, when the dumpadm
 217            settings from the previous boot must be restored. Your dump
 218            configuration is saved in the configuration file for this purpose.
 219            If the configuration file is missing or contains invalid values for
 220            any dump properties, the default values are substituted. Following
 221            the update, the configuration file is resynchronized with the
 222            kernel dump configuration.
 223 
 224 
 225        -y
 226 
 227            Modify the dump configuration to automatically run savecore on
 228            reboot.  This is the default for this dump setting.
 229 
 230 
 231        -z on | off
 232 
 233            Turns crash dump compression on or off.
 234 
 235 
 236 EXAMPLES
 237        Example 1 Reconfiguring The Dump Device To A Dedicated Dump Device:
 238 
 239 
 240        The following command reconfigures the dump device to a dedicated dump
 241        device:
 242 
 243 
 244          example# dumpadm -d /dev/dsk/c0t2d0s2
 245 
 246                     Dump content: kernel pages
 247                      Dump device: /dev/dsk/c0t2d0s2 (dedicated)
 248               Savecore directory: /var/crash
 249                 Savecore enabled: yes
 250                  Save compressed: on
 251 
 252 
 253 
 254 EXIT STATUS
 255        The following exit values are returned:
 256 
 257        0
 258 
 259            Dump configuration is valid and the specified modifications, if
 260            any, were made successfully.
 261 
 262 
 263        1
 264 
 265            A fatal error occurred in either obtaining or modifying the dump
 266            configuration.
 267 
 268 


 338    Minimum Free Space
 339        If the dumpadm -m option is used to create a minfree file based on a
 340        percentage of the total size of the file system containing the savecore
 341        directory, this value is not automatically recomputed if the file
 342        system subsequently changes size.  In this case, the administrator must
 343        re-execute dumpadm -m to recompute the minfree value. If no such file
 344        exists in the savecore directory, savecore will default to a free space
 345        threshold of one megabyte. If no free space threshold is desired, a
 346        minfree file containing size 0 can be created.
 347 
 348    Security Issues
 349        If, upon reboot, the specified savecore directory is not present, it
 350        will be created prior to the execution of savecore with permissions
 351        0700 (read, write, execute by owner only) and owner root. It is
 352        recommended that alternate savecore directories also be created with
 353        similar permissions, as the operating system crash dump files
 354        themselves may contain secure information.
 355 
 356 
 357 
 358                                February 13, 2017                   DUMPADM(1M)