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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>
   1 '\" te
   2 .\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved
   3 .\" Copyright 2015 Nexenta Systems, Inc.  All Rights Reserved.
   4 .\" Copyright (c) 2013 by Delphix. All rights reserved.
   5 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
   6 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
   7 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
   8 .TH DUMPADM 1M "Apr 09, 2015"
   9 .SH NAME
  10 dumpadm \- configure operating system crash dump
  11 .SH SYNOPSIS
  12 .LP
  13 .nf
  14 \fB/usr/sbin/dumpadm\fR [\fB-enuy\fR] [\fB-c\fR \fIcontent-type\fR] [\fB-d\fR \fIdump-device\fR]
  15      [\fB-m\fR \fImin\fRk | \fImin\fRm | \fImin\fR%] [\fB-s\fR \fIsavecore-dir\fR]
  16      [\fB-r\fR \fIroot-dir\fR] [\fB-z\fR on | off]
  17 .fi
  18 
  19 .SH DESCRIPTION
  20 .sp
  21 .LP
  22 The \fBdumpadm\fR program is an administrative command that manages the
  23 configuration of the operating system crash dump facility. A crash dump is a
  24 disk copy of the physical memory of the computer at the time of a fatal system
  25 error. When a fatal operating system error occurs, a message describing the
  26 error is printed to the console. The operating system then generates a crash
  27 dump by writing the contents of physical memory to a predetermined dump device,
  28 which is typically a local disk partition. The dump device can be configured by
  29 way of \fBdumpadm\fR. Once the crash dump has been written to the dump device,
  30 the system will reboot.
  31 .sp
  32 .LP
  33 Fatal operating system errors can be caused by bugs in the operating system,
  34 its associated device drivers and loadable modules, or by faulty hardware.
  35 Whatever the cause, the crash dump itself provides invaluable information to
  36 your support engineer to aid in diagnosing the problem. As such, it is vital
  37 that the crash dump be retrieved and given to your support provider. Following
  38 an operating system crash, the \fBsavecore\fR(1M) utility is executed
  39 automatically during boot to retrieve the crash dump from the dump device, and
  40 write it to the file system. The directory in which the crash


  48 writes two files named \fIunix.X\fR and \fIvmcore.X\fR. In the uncompressed
  49 case, both data files form the \fIsaved crash dump\fR. In both cases X is an
  50 integer identifying the dump.
  51 .sp
  52 .LP
  53 For systems with a UFS root file system, the default dump device is  configured
  54 to be an appropriate swap partition. Swap partitions are disk partitions
  55 reserved as virtual memory backing store for the operating system. Thus, no
  56 permanent information resides in swap to be overwritten by the dump. See
  57 \fBswap\fR(1M). For systems with a ZFS root file system, dedicated ZFS volumes
  58 are used for swap and dump areas. For further information about setting up a
  59 dump area with ZFS,  see the \fIZFS Administration Guide\fR. To view the
  60 current dump  configuration, use the \fBdumpadm\fR command with no arguments:
  61 .sp
  62 .in +2
  63 .nf
  64 example# \fBdumpadm\fR
  65 
  66       Dump content: kernel pages
  67        Dump device: /dev/dsk/c0t0d0s1 (swap)
  68 Savecore directory: /var/crash/saturn
  69   Savecore enabled: yes
  70    Save compressed: on
  71 .fi
  72 .in -2
  73 .sp
  74 
  75 .sp
  76 .LP
  77 When no options are specified, \fBdumpadm\fR prints the current crash dump
  78 configuration. The example shows the set of default values: the dump content is
  79 set to kernel memory pages only, the dump device is a swap disk partition, the
  80 directory for \fBsavecore\fR files is set to
  81 \fB/var/crash/\fR\fIhostname\fR\fB,\fR \fBsavecore\fR is set to run
  82 automatically on reboot, and compression is turned on.
  83 .sp
  84 .LP
  85 When one or more options are specified, \fBdumpadm\fR verifies that your
  86 changes are valid, and if so, reconfigures the crash dump parameters and
  87 displays the resulting configuration. You must be \fBroot\fR to view or change
  88 dump parameters.
  89 .SH OPTIONS
  90 .sp
  91 .LP
  92 The following options are supported:
  93 .sp
  94 .ne 2
  95 .na
  96 \fB\fB-c\fR \fIcontent-type\fR\fR
  97 .ad
  98 .sp .6
  99 .RS 4n
 100 Modify the dump configuration so that the crash dump consists of the specified
 101 dump content. The content should be one of the following:
 102 .sp
 103 .ne 2
 104 .na
 105 \fB\fBkernel\fR\fR
 106 .ad
 107 .sp .6
 108 .RS 4n
 109 Kernel memory pages only.
 110 .RE


 269 .ad
 270 .sp .6
 271 .RS 4n
 272 Specify an alternate root directory relative to which \fBdumpadm\fR should
 273 create files. If no \fB-r\fR argument is specified, the default root directory
 274 \fB/\fR is used.
 275 .RE
 276 
 277 .sp
 278 .ne 2
 279 .na
 280 \fB\fB-s\fR \fIsavecore-dir\fR\fR
 281 .ad
 282 .sp .6
 283 .RS 4n
 284 Modify the dump configuration to use the specified directory to save files
 285 written by \fBsavecore\fR. The directory should be an absolute path and exist
 286 on the system. If upon reboot the directory does not exist, it will be created
 287 prior to the execution of \fBsavecore\fR. See the \fBNOTES\fR section below for
 288 a discussion of security issues relating to access to the savecore directory.
 289 The default savecore directory is \fB/var/crash/\fIhostname\fR\fR where
 290 \fIhostname\fR is the output of the \fB-n\fR option to the \fBuname\fR(1)
 291 command.
 292 .RE
 293 
 294 .sp
 295 .ne 2
 296 .na
 297 \fB\fB-u\fR\fR
 298 .ad
 299 .sp .6
 300 .RS 4n
 301 Forcibly update the kernel dump configuration based on the contents of
 302 \fB/etc/dumpadm.conf\fR. Normally this option is used only on reboot when
 303 starting \fBsvc:/system/dumpadm:default\fR, when the \fBdumpadm\fR settings
 304 from the previous boot must be restored. Your dump configuration is saved in
 305 the configuration file for this purpose. If the configuration file is missing
 306 or contains invalid values for any dump properties, the default values are
 307 substituted. Following the update, the configuration file is resynchronized
 308 with the kernel dump configuration.
 309 .RE
 310 
 311 .sp


 326 .ad
 327 .sp .6
 328 .RS 4n
 329 Turns crash dump compression \fBon\fR or \fBoff\fR.
 330 .RE
 331 
 332 .SH EXAMPLES
 333 .LP
 334 \fBExample 1 \fRReconfiguring The Dump Device To A Dedicated Dump Device:
 335 .sp
 336 .LP
 337 The following command reconfigures the dump device to a dedicated dump device:
 338 
 339 .sp
 340 .in +2
 341 .nf
 342 example# dumpadm -d /dev/dsk/c0t2d0s2
 343 
 344            Dump content: kernel pages
 345             Dump device: /dev/dsk/c0t2d0s2 (dedicated)
 346      Savecore directory: /var/crash/saturn
 347        Savecore enabled: yes
 348         Save compressed: on
 349 .fi
 350 .in -2
 351 .sp
 352 
 353 .SH EXIT STATUS
 354 .sp
 355 .LP
 356 The following exit values are returned:
 357 .sp
 358 .ne 2
 359 .na
 360 \fB\fB0\fR\fR
 361 .ad
 362 .sp .6
 363 .RS 4n
 364 Dump configuration is valid and the specified modifications, if any, were made
 365 successfully.
 366 .RE
 367 
 368 .sp
 369 .ne 2
 370 .na
 371 \fB\fB1\fR\fR
 372 .ad
 373 .sp .6
 374 .RS 4n
 375 A fatal error occurred in either obtaining or modifying the dump configuration.
 376 .RE
 377 
 378 .sp
 379 .ne 2
 380 .na
 381 \fB\fB2\fR\fR
 382 .ad
 383 .sp .6
 384 .RS 4n
 385 Invalid command line options were specified.
 386 .RE
 387 
 388 .SH FILES
 389 .sp
 390 .ne 2
 391 .na
 392 \fB\fB/dev/dump\fR\fR
 393 .ad
 394 .sp .6
 395 .RS 4n
 396 Dump device.
 397 .RE
 398 
 399 .sp
 400 .ne 2
 401 .na
 402 \fB\fB/etc/dumpadm.conf\fR\fR
 403 .ad
 404 .sp .6
 405 .RS 4n
 406 Contains configuration parameters for \fBdumpadm\fR. Modifiable only through
 407 that command.
 408 .RE
 409 
 410 .sp
 411 .ne 2
 412 .na
 413 \fB\fIsavecore-directory\fR\fB/minfree\fR\fR
 414 .ad
 415 .sp .6
 416 .RS 4n
 417 Contains minimum amount of free space for \fIsavecore-directory\fR. See
 418 \fBsavecore\fR(1M).
 419 .RE
 420 
 421 .SH SEE ALSO
 422 .sp
 423 .LP
 424 \fBsvcs\fR(1), \fBuname\fR(1), \fBsavecore\fR(1M), \fBsvcadm\fR(1M),
 425 \fBswap\fR(1M), \fBattributes\fR(5), \fBsmf\fR(5)
 426 .SH NOTES
 427 .sp
 428 .LP
 429 The system crash dump service is managed by the service management facility,
 430 \fBsmf\fR(5), under the service identifier:
 431 .sp
 432 .in +2
 433 .nf
 434 svc:/system/dumpadm:default
 435 .fi
 436 .in -2
 437 .sp
 438 
 439 .sp
 440 .LP
 441 Administrative actions on this service, such as enabling, disabling, or
 442 requesting restart, can be performed using \fBsvcadm\fR(1M). The service's
 443 status can be queried using the \fBsvcs\fR(1) command.
 444 .SS "Dump Device Selection"
 445 .sp
 446 .LP
 447 When the special \fBswap\fR token is specified as the argument to \fBdumpadm\fR
 448 \fB-d\fR the utility will attempt to configure the most appropriate swap device
 449 as the dump device. \fBdumpadm\fR configures the largest swap block device as
 450 the dump device; if no block devices are available for swap, the largest swap
 451 entry is configured as the dump device. If no swap entries are present, or none
 452 can be configured as the dump device, a warning message will be displayed.
 453 While local and remote swap files can be configured as the dump device, this is
 454 not recommended.
 455 .SS "Dump Device/Swap Device Interaction (UFS File Systems Only)"
 456 .sp
 457 .LP
 458 In the event that the dump device is also a swap device, and the swap device is
 459 deleted by the administrator using the \fBswap\fR \fB-d\fR command, the
 460 \fBswap\fR command will automatically invoke \fBdumpadm\fR \fB-d\fR \fBswap\fR
 461 in order to attempt to configure another appropriate swap device as the dump
 462 device. If no swap devices remain or none can be configured as the dump device,
 463 the crash dump will be disabled and a warning message will be displayed.
 464 Similarly, if the crash dump is disabled and the administrator adds a new swap
 465 device using the \fBswap\fR \fB-a\fR command, \fBdumpadm\fR \fB-d\fR \fBswap\fR
 466 will be invoked to re-enable the crash dump using the new swap device.
 467 .sp
 468 .LP
 469 Once \fBdumpadm\fR \fB-d\fR \fBswap\fR has been issued, the new dump device is
 470 stored in the configuration file for subsequent reboots. If a larger or more
 471 appropriate swap device is added by the administrator, the dump device is not
 472 changed; the administrator must re-execute \fBdumpadm\fR \fB-d\fR \fBswap\fR to
 473 reselect the most appropriate device fom the new list of swap devices.
 474 .SS "Minimum Free Space"
 475 .sp
 476 .LP
 477 If the \fBdumpadm\fR \fB-m\fR option is used to create a \fBminfree\fR file
 478 based on a percentage of the total size of the file system containing the
 479 savecore directory, this value is not automatically recomputed if the file
 480 system subsequently changes size.  In this case, the administrator must
 481 re-execute \fBdumpadm\fR \fB-m\fR to recompute the \fBminfree\fR value. If no
 482 such file exists in the savecore directory, \fBsavecore\fR will default to a
 483 free space threshold of one megabyte. If no free space threshold is desired, a
 484 minfree file containing size 0 can be created.
 485 .SS "Security Issues"
 486 .sp
 487 .LP
 488 If, upon reboot, the specified savecore directory is not present, it will be
 489 created prior to the execution of \fBsavecore\fR with permissions 0700 (read,
 490 write, execute by owner only) and owner \fBroot\fR. It is recommended that
 491 alternate savecore directories also be created with similar permissions, as the
 492 operating system crash dump files themselves may contain secure information.
   1 '\" te
   2 .\" Copyright (c) 2008, Sun Microsystems, Inc. All Rights Reserved
   3 .\" Copyright 2017 Nexenta Systems, Inc.  All Rights Reserved.
   4 .\" Copyright (c) 2013 by Delphix. All rights reserved.
   5 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
   6 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
   7 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
   8 .TH DUMPADM 1M "Feb 13, 2017"
   9 .SH NAME
  10 dumpadm \- configure operating system crash dump
  11 .SH SYNOPSIS
  12 .LP
  13 .nf
  14 \fB/usr/sbin/dumpadm\fR [\fB-enuy\fR] [\fB-c\fR \fIcontent-type\fR] [\fB-d\fR \fIdump-device\fR]
  15      [\fB-m\fR \fImin\fRk | \fImin\fRm | \fImin\fR%] [\fB-s\fR \fIsavecore-dir\fR]
  16      [\fB-r\fR \fIroot-dir\fR] [\fB-z\fR on | off]
  17 .fi
  18 
  19 .SH DESCRIPTION

  20 .LP
  21 The \fBdumpadm\fR program is an administrative command that manages the
  22 configuration of the operating system crash dump facility. A crash dump is a
  23 disk copy of the physical memory of the computer at the time of a fatal system
  24 error. When a fatal operating system error occurs, a message describing the
  25 error is printed to the console. The operating system then generates a crash
  26 dump by writing the contents of physical memory to a predetermined dump device,
  27 which is typically a local disk partition. The dump device can be configured by
  28 way of \fBdumpadm\fR. Once the crash dump has been written to the dump device,
  29 the system will reboot.
  30 .sp
  31 .LP
  32 Fatal operating system errors can be caused by bugs in the operating system,
  33 its associated device drivers and loadable modules, or by faulty hardware.
  34 Whatever the cause, the crash dump itself provides invaluable information to
  35 your support engineer to aid in diagnosing the problem. As such, it is vital
  36 that the crash dump be retrieved and given to your support provider. Following
  37 an operating system crash, the \fBsavecore\fR(1M) utility is executed
  38 automatically during boot to retrieve the crash dump from the dump device, and
  39 write it to the file system. The directory in which the crash


  47 writes two files named \fIunix.X\fR and \fIvmcore.X\fR. In the uncompressed
  48 case, both data files form the \fIsaved crash dump\fR. In both cases X is an
  49 integer identifying the dump.
  50 .sp
  51 .LP
  52 For systems with a UFS root file system, the default dump device is  configured
  53 to be an appropriate swap partition. Swap partitions are disk partitions
  54 reserved as virtual memory backing store for the operating system. Thus, no
  55 permanent information resides in swap to be overwritten by the dump. See
  56 \fBswap\fR(1M). For systems with a ZFS root file system, dedicated ZFS volumes
  57 are used for swap and dump areas. For further information about setting up a
  58 dump area with ZFS,  see the \fIZFS Administration Guide\fR. To view the
  59 current dump  configuration, use the \fBdumpadm\fR command with no arguments:
  60 .sp
  61 .in +2
  62 .nf
  63 example# \fBdumpadm\fR
  64 
  65       Dump content: kernel pages
  66        Dump device: /dev/dsk/c0t0d0s1 (swap)
  67 Savecore directory: /var/crash
  68   Savecore enabled: yes
  69    Save compressed: on
  70 .fi
  71 .in -2
  72 .sp
  73 
  74 .sp
  75 .LP
  76 When no options are specified, \fBdumpadm\fR prints the current crash dump
  77 configuration. The example shows the set of default values: the dump content is
  78 set to kernel memory pages only, the dump device is a swap disk partition, the
  79 directory for \fBsavecore\fR files is set to
  80 \fB/var/crash\fR, \fBsavecore\fR is set to run
  81 automatically on reboot, and compression is turned on.
  82 .sp
  83 .LP
  84 When one or more options are specified, \fBdumpadm\fR verifies that your
  85 changes are valid, and if so, reconfigures the crash dump parameters and
  86 displays the resulting configuration. You must be \fBroot\fR to view or change
  87 dump parameters.
  88 .SH OPTIONS

  89 .LP
  90 The following options are supported:
  91 .sp
  92 .ne 2
  93 .na
  94 \fB\fB-c\fR \fIcontent-type\fR\fR
  95 .ad
  96 .sp .6
  97 .RS 4n
  98 Modify the dump configuration so that the crash dump consists of the specified
  99 dump content. The content should be one of the following:
 100 .sp
 101 .ne 2
 102 .na
 103 \fB\fBkernel\fR\fR
 104 .ad
 105 .sp .6
 106 .RS 4n
 107 Kernel memory pages only.
 108 .RE


 267 .ad
 268 .sp .6
 269 .RS 4n
 270 Specify an alternate root directory relative to which \fBdumpadm\fR should
 271 create files. If no \fB-r\fR argument is specified, the default root directory
 272 \fB/\fR is used.
 273 .RE
 274 
 275 .sp
 276 .ne 2
 277 .na
 278 \fB\fB-s\fR \fIsavecore-dir\fR\fR
 279 .ad
 280 .sp .6
 281 .RS 4n
 282 Modify the dump configuration to use the specified directory to save files
 283 written by \fBsavecore\fR. The directory should be an absolute path and exist
 284 on the system. If upon reboot the directory does not exist, it will be created
 285 prior to the execution of \fBsavecore\fR. See the \fBNOTES\fR section below for
 286 a discussion of security issues relating to access to the savecore directory.
 287 The default savecore directory is \fB/var/crash\fR.


 288 .RE
 289 
 290 .sp
 291 .ne 2
 292 .na
 293 \fB\fB-u\fR\fR
 294 .ad
 295 .sp .6
 296 .RS 4n
 297 Forcibly update the kernel dump configuration based on the contents of
 298 \fB/etc/dumpadm.conf\fR. Normally this option is used only on reboot when
 299 starting \fBsvc:/system/dumpadm:default\fR, when the \fBdumpadm\fR settings
 300 from the previous boot must be restored. Your dump configuration is saved in
 301 the configuration file for this purpose. If the configuration file is missing
 302 or contains invalid values for any dump properties, the default values are
 303 substituted. Following the update, the configuration file is resynchronized
 304 with the kernel dump configuration.
 305 .RE
 306 
 307 .sp


 322 .ad
 323 .sp .6
 324 .RS 4n
 325 Turns crash dump compression \fBon\fR or \fBoff\fR.
 326 .RE
 327 
 328 .SH EXAMPLES
 329 .LP
 330 \fBExample 1 \fRReconfiguring The Dump Device To A Dedicated Dump Device:
 331 .sp
 332 .LP
 333 The following command reconfigures the dump device to a dedicated dump device:
 334 
 335 .sp
 336 .in +2
 337 .nf
 338 example# dumpadm -d /dev/dsk/c0t2d0s2
 339 
 340            Dump content: kernel pages
 341             Dump device: /dev/dsk/c0t2d0s2 (dedicated)
 342      Savecore directory: /var/crash
 343        Savecore enabled: yes
 344         Save compressed: on
 345 .fi
 346 .in -2
 347 .sp
 348 
 349 .SH EXIT STATUS

 350 .LP
 351 The following exit values are returned:
 352 .sp
 353 .ne 2
 354 .na
 355 \fB\fB0\fR\fR
 356 .ad
 357 .sp .6
 358 .RS 4n
 359 Dump configuration is valid and the specified modifications, if any, were made
 360 successfully.
 361 .RE
 362 
 363 .sp
 364 .ne 2
 365 .na
 366 \fB\fB1\fR\fR
 367 .ad
 368 .sp .6
 369 .RS 4n
 370 A fatal error occurred in either obtaining or modifying the dump configuration.
 371 .RE
 372 
 373 .sp
 374 .ne 2
 375 .na
 376 \fB\fB2\fR\fR
 377 .ad
 378 .sp .6
 379 .RS 4n
 380 Invalid command line options were specified.
 381 .RE
 382 
 383 .SH FILES

 384 .ne 2
 385 .na
 386 \fB\fB/dev/dump\fR\fR
 387 .ad
 388 .sp .6
 389 .RS 4n
 390 Dump device.
 391 .RE
 392 
 393 .sp
 394 .ne 2
 395 .na
 396 \fB\fB/etc/dumpadm.conf\fR\fR
 397 .ad
 398 .sp .6
 399 .RS 4n
 400 Contains configuration parameters for \fBdumpadm\fR. Modifiable only through
 401 that command.
 402 .RE
 403 
 404 .sp
 405 .ne 2
 406 .na
 407 \fB\fIsavecore-directory\fR\fB/minfree\fR\fR
 408 .ad
 409 .sp .6
 410 .RS 4n
 411 Contains minimum amount of free space for \fIsavecore-directory\fR. See
 412 \fBsavecore\fR(1M).
 413 .RE
 414 
 415 .SH SEE ALSO

 416 .LP
 417 \fBsvcs\fR(1), \fBuname\fR(1), \fBsavecore\fR(1M), \fBsvcadm\fR(1M),
 418 \fBswap\fR(1M), \fBattributes\fR(5), \fBsmf\fR(5)
 419 .SH NOTES

 420 .LP
 421 The system crash dump service is managed by the service management facility,
 422 \fBsmf\fR(5), under the service identifier:
 423 .sp
 424 .in +2
 425 .nf
 426 svc:/system/dumpadm:default
 427 .fi
 428 .in -2
 429 .sp
 430 
 431 .sp
 432 .LP
 433 Administrative actions on this service, such as enabling, disabling, or
 434 requesting restart, can be performed using \fBsvcadm\fR(1M). The service's
 435 status can be queried using the \fBsvcs\fR(1) command.
 436 .SS "Dump Device Selection"

 437 .LP
 438 When the special \fBswap\fR token is specified as the argument to \fBdumpadm\fR
 439 \fB-d\fR the utility will attempt to configure the most appropriate swap device
 440 as the dump device. \fBdumpadm\fR configures the largest swap block device as
 441 the dump device; if no block devices are available for swap, the largest swap
 442 entry is configured as the dump device. If no swap entries are present, or none
 443 can be configured as the dump device, a warning message will be displayed.
 444 While local and remote swap files can be configured as the dump device, this is
 445 not recommended.
 446 .SS "Dump Device/Swap Device Interaction (UFS File Systems Only)"

 447 .LP
 448 In the event that the dump device is also a swap device, and the swap device is
 449 deleted by the administrator using the \fBswap\fR \fB-d\fR command, the
 450 \fBswap\fR command will automatically invoke \fBdumpadm\fR \fB-d\fR \fBswap\fR
 451 in order to attempt to configure another appropriate swap device as the dump
 452 device. If no swap devices remain or none can be configured as the dump device,
 453 the crash dump will be disabled and a warning message will be displayed.
 454 Similarly, if the crash dump is disabled and the administrator adds a new swap
 455 device using the \fBswap\fR \fB-a\fR command, \fBdumpadm\fR \fB-d\fR \fBswap\fR
 456 will be invoked to re-enable the crash dump using the new swap device.
 457 .sp
 458 .LP
 459 Once \fBdumpadm\fR \fB-d\fR \fBswap\fR has been issued, the new dump device is
 460 stored in the configuration file for subsequent reboots. If a larger or more
 461 appropriate swap device is added by the administrator, the dump device is not
 462 changed; the administrator must re-execute \fBdumpadm\fR \fB-d\fR \fBswap\fR to
 463 reselect the most appropriate device fom the new list of swap devices.
 464 .SS "Minimum Free Space"

 465 .LP
 466 If the \fBdumpadm\fR \fB-m\fR option is used to create a \fBminfree\fR file
 467 based on a percentage of the total size of the file system containing the
 468 savecore directory, this value is not automatically recomputed if the file
 469 system subsequently changes size.  In this case, the administrator must
 470 re-execute \fBdumpadm\fR \fB-m\fR to recompute the \fBminfree\fR value. If no
 471 such file exists in the savecore directory, \fBsavecore\fR will default to a
 472 free space threshold of one megabyte. If no free space threshold is desired, a
 473 minfree file containing size 0 can be created.
 474 .SS "Security Issues"

 475 .LP
 476 If, upon reboot, the specified savecore directory is not present, it will be
 477 created prior to the execution of \fBsavecore\fR with permissions 0700 (read,
 478 write, execute by owner only) and owner \fBroot\fR. It is recommended that
 479 alternate savecore directories also be created with similar permissions, as the
 480 operating system crash dump files themselves may contain secure information.