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>
| Split |
Close |
| Expand all |
| Collapse all |
--- old/usr/src/man/man1m/dumpadm.1m.man.txt
+++ new/usr/src/man/man1m/dumpadm.1m.man.txt
1 1 DUMPADM(1M) Maintenance Commands DUMPADM(1M)
2 2
3 3
4 4
5 5 NAME
6 6 dumpadm - configure operating system crash dump
7 7
8 8 SYNOPSIS
9 9 /usr/sbin/dumpadm [-enuy] [-c content-type] [-d dump-device]
10 10 [-m mink | minm | min%] [-s savecore-dir]
11 11 [-r root-dir] [-z on | off]
12 12
13 13
14 14 DESCRIPTION
15 15 The dumpadm program is an administrative command that manages the
16 16 configuration of the operating system crash dump facility. A crash dump
17 17 is a disk copy of the physical memory of the computer at the time of a
18 18 fatal system error. When a fatal operating system error occurs, a
19 19 message describing the error is printed to the console. The operating
20 20 system then generates a crash dump by writing the contents of physical
21 21 memory to a predetermined dump device, which is typically a local disk
22 22 partition. The dump device can be configured by way of dumpadm. Once
23 23 the crash dump has been written to the dump device, the system will
24 24 reboot.
25 25
26 26
27 27 Fatal operating system errors can be caused by bugs in the operating
28 28 system, its associated device drivers and loadable modules, or by
29 29 faulty hardware. Whatever the cause, the crash dump itself provides
30 30 invaluable information to your support engineer to aid in diagnosing
31 31 the problem. As such, it is vital that the crash dump be retrieved and
32 32 given to your support provider. Following an operating system crash,
33 33 the savecore(1M) utility is executed automatically during boot to
34 34 retrieve the crash dump from the dump device, and write it to the file
35 35 system. The directory in which the crash dump is saved on reboot can
36 36 also be configured using dumpadm.
37 37
38 38
39 39 When the operating system takes a crash dump the default behavior is to
40 40 compress the crash dump. This behavior is controlled by the -z option.
41 41 When compression is turned on, the savecore(1M) utility writes one file
42 42 to the file system named vmdump.X. If compression is disabled, it
43 43 instead writes two files named unix.X and vmcore.X. In the uncompressed
44 44 case, both data files form the saved crash dump. In both cases X is an
45 45 integer identifying the dump.
46 46
47 47
48 48 For systems with a UFS root file system, the default dump device is
49 49 configured to be an appropriate swap partition. Swap partitions are
50 50 disk partitions reserved as virtual memory backing store for the
51 51 operating system. Thus, no permanent information resides in swap to be
|
↓ open down ↓ |
51 lines elided |
↑ open up ↑ |
52 52 overwritten by the dump. See swap(1M). For systems with a ZFS root file
53 53 system, dedicated ZFS volumes are used for swap and dump areas. For
54 54 further information about setting up a dump area with ZFS, see the ZFS
55 55 Administration Guide. To view the current dump configuration, use the
56 56 dumpadm command with no arguments:
57 57
58 58 example# dumpadm
59 59
60 60 Dump content: kernel pages
61 61 Dump device: /dev/dsk/c0t0d0s1 (swap)
62 - Savecore directory: /var/crash/saturn
62 + Savecore directory: /var/crash
63 63 Savecore enabled: yes
64 64 Save compressed: on
65 65
66 66
67 67
68 68
69 69 When no options are specified, dumpadm prints the current crash dump
70 70 configuration. The example shows the set of default values: the dump
71 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.
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 75
76 76
77 77 When one or more options are specified, dumpadm verifies that your
78 78 changes are valid, and if so, reconfigures the crash dump parameters
79 79 and displays the resulting configuration. You must be root to view or
80 80 change dump parameters.
81 81
82 82 OPTIONS
83 83 The following options are supported:
84 84
85 85 -c content-type
86 86
87 87 Modify the dump configuration so that the crash dump consists of
88 88 the specified dump content. The content should be one of the
89 89 following:
90 90
91 91 kernel
92 92
93 93 Kernel memory pages only.
94 94
95 95
96 96 all
97 97
98 98 All memory pages.
99 99
100 100
101 101 curproc
102 102
103 103 Kernel memory pages, and the memory pages of the process whose
104 104 thread was currently executing on the CPU on which the crash
105 105 dump was initiated. If the thread executing on that CPU is a
106 106 kernel thread not associated with any user process, only kernel
107 107 pages will be dumped.
108 108
109 109
110 110
111 111 -d dump-device
112 112
113 113 Modify the dump configuration to use the specified dump device. The
114 114 dump device may be one of the following:
115 115
116 116 dump-device
117 117
118 118 A specific dump device specified as an absolute pathname, such
119 119 as /dev/dsk/cNtNdNsN when the system is running a UFS root file
120 120 system. Or, specify a ZFS volume, such as
121 121 /dev/zvol/dsk/rpool/dump, when the system is running a ZFS root
122 122 file system.
123 123
124 124
125 125 swap
126 126
127 127 If the special token swap is specified as the dump device,
128 128 dumpadm examines the active swap entries and selects the most
129 129 appropriate entry to configure as the dump device. See
130 130 swap(1M). Refer to the NOTES below for details of the algorithm
131 131 used to select an appropriate swap entry. When the system is
132 132 first installed with a UFS root file system, dumpadm uses the
133 133 value for swap to determine the initial dump device setting. A
134 134 given ZFS volume cannot be configured for both the swap area
135 135 and the dump device.
136 136
137 137
138 138 none
139 139
140 140 If the special token none is specified, the active dump device
141 141 is removed and crash dumps are disabled.
142 142
143 143
144 144
145 145 -e
146 146
147 147 Estimates the size of the dump for the current running system.
148 148
149 149
150 150 -m mink | minm | min%
151 151
152 152 Create a minfree file in the current savecore directory indicating
153 153 that savecore should maintain at least the specified amount of free
154 154 space in the file system where the savecore directory is located.
155 155 The min argument can be one of the following:
156 156
157 157 k
158 158
159 159 A positive integer suffixed with the unit k specifying
160 160 kilobytes.
161 161
162 162
163 163 m
164 164
165 165 A positive integer suffixed with the unit m specifying
166 166 megabytes.
167 167
168 168
169 169 %
170 170
171 171 A % symbol, indicating that the minfree value should be
172 172 computed as the specified percentage of the total current size
173 173 of the file system containing the savecore directory.
174 174
175 175 The savecore command will consult the minfree file, if present,
176 176 prior to writing the dump files. If the size of these files would
177 177 decrease the amount of free disk space below the minfree threshold,
178 178 no dump files are written and an error message is logged. The
179 179 administrator should immediately clean up the savecore directory to
180 180 provide adequate free space, and re-execute the savecore command
181 181 manually. The administrator can also specify an alternate directory
182 182 on the savecore command-line.
183 183
184 184
185 185 -n
186 186
187 187 Modify the dump configuration to not run savecore automatically on
188 188 reboot. This is not the recommended system configuration; if the
189 189 dump device is a swap partition, the dump data will be overwritten
190 190 as the system begins to swap. If savecore is not executed shortly
191 191 after boot, crash dump retrieval may not be possible.
192 192
193 193
194 194 -r root-dir
195 195
196 196 Specify an alternate root directory relative to which dumpadm
197 197 should create files. If no -r argument is specified, the default
198 198 root directory / is used.
|
↓ open down ↓ |
114 lines elided |
↑ open up ↑ |
199 199
200 200
201 201 -s savecore-dir
202 202
203 203 Modify the dump configuration to use the specified directory to
204 204 save files written by savecore. The directory should be an absolute
205 205 path and exist on the system. If upon reboot the directory does not
206 206 exist, it will be created prior to the execution of savecore. See
207 207 the NOTES section below for a discussion of security issues
208 208 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.
209 + directory is /var/crash.
211 210
212 211
213 212 -u
214 213
215 214 Forcibly update the kernel dump configuration based on the contents
216 215 of /etc/dumpadm.conf. Normally this option is used only on reboot
217 216 when starting svc:/system/dumpadm:default, when the dumpadm
218 217 settings from the previous boot must be restored. Your dump
219 218 configuration is saved in the configuration file for this purpose.
220 219 If the configuration file is missing or contains invalid values for
221 220 any dump properties, the default values are substituted. Following
222 221 the update, the configuration file is resynchronized with the
223 222 kernel dump configuration.
224 223
225 224
226 225 -y
227 226
228 227 Modify the dump configuration to automatically run savecore on
229 228 reboot. This is the default for this dump setting.
230 229
231 230
232 231 -z on | off
233 232
234 233 Turns crash dump compression on or off.
235 234
236 235
237 236 EXAMPLES
238 237 Example 1 Reconfiguring The Dump Device To A Dedicated Dump Device:
|
↓ open down ↓ |
18 lines elided |
↑ open up ↑ |
239 238
240 239
241 240 The following command reconfigures the dump device to a dedicated dump
242 241 device:
243 242
244 243
245 244 example# dumpadm -d /dev/dsk/c0t2d0s2
246 245
247 246 Dump content: kernel pages
248 247 Dump device: /dev/dsk/c0t2d0s2 (dedicated)
249 - Savecore directory: /var/crash/saturn
248 + Savecore directory: /var/crash
250 249 Savecore enabled: yes
251 250 Save compressed: on
252 251
253 252
254 253
255 254 EXIT STATUS
256 255 The following exit values are returned:
257 256
258 257 0
259 258
260 259 Dump configuration is valid and the specified modifications, if
261 260 any, were made successfully.
262 261
263 262
264 263 1
265 264
266 265 A fatal error occurred in either obtaining or modifying the dump
267 266 configuration.
268 267
269 268
270 269 2
271 270
272 271 Invalid command line options were specified.
273 272
274 273
275 274 FILES
276 275 /dev/dump
277 276
278 277 Dump device.
279 278
280 279
281 280 /etc/dumpadm.conf
282 281
283 282 Contains configuration parameters for dumpadm. Modifiable only
284 283 through that command.
285 284
286 285
287 286 savecore-directory/minfree
288 287
289 288 Contains minimum amount of free space for savecore-directory. See
290 289 savecore(1M).
291 290
292 291
293 292 SEE ALSO
294 293 svcs(1), uname(1), savecore(1M), svcadm(1M), swap(1M), attributes(5),
295 294 smf(5)
296 295
297 296 NOTES
298 297 The system crash dump service is managed by the service management
299 298 facility, smf(5), under the service identifier:
300 299
301 300 svc:/system/dumpadm:default
302 301
303 302
304 303
305 304
306 305 Administrative actions on this service, such as enabling, disabling, or
307 306 requesting restart, can be performed using svcadm(1M). The service's
308 307 status can be queried using the svcs(1) command.
309 308
310 309 Dump Device Selection
311 310 When the special swap token is specified as the argument to dumpadm -d
312 311 the utility will attempt to configure the most appropriate swap device
313 312 as the dump device. dumpadm configures the largest swap block device as
314 313 the dump device; if no block devices are available for swap, the
315 314 largest swap entry is configured as the dump device. If no swap entries
316 315 are present, or none can be configured as the dump device, a warning
317 316 message will be displayed. While local and remote swap files can be
318 317 configured as the dump device, this is not recommended.
319 318
320 319 Dump Device/Swap Device Interaction (UFS File Systems Only)
321 320 In the event that the dump device is also a swap device, and the swap
322 321 device is deleted by the administrator using the swap -d command, the
323 322 swap command will automatically invoke dumpadm -d swap in order to
324 323 attempt to configure another appropriate swap device as the dump
325 324 device. If no swap devices remain or none can be configured as the dump
326 325 device, the crash dump will be disabled and a warning message will be
327 326 displayed. Similarly, if the crash dump is disabled and the
328 327 administrator adds a new swap device using the swap -a command, dumpadm
329 328 -d swap will be invoked to re-enable the crash dump using the new swap
330 329 device.
331 330
332 331
333 332 Once dumpadm -d swap has been issued, the new dump device is stored in
334 333 the configuration file for subsequent reboots. If a larger or more
335 334 appropriate swap device is added by the administrator, the dump device
336 335 is not changed; the administrator must re-execute dumpadm -d swap to
337 336 reselect the most appropriate device fom the new list of swap devices.
338 337
339 338 Minimum Free Space
340 339 If the dumpadm -m option is used to create a minfree file based on a
341 340 percentage of the total size of the file system containing the savecore
342 341 directory, this value is not automatically recomputed if the file
343 342 system subsequently changes size. In this case, the administrator must
344 343 re-execute dumpadm -m to recompute the minfree value. If no such file
345 344 exists in the savecore directory, savecore will default to a free space
346 345 threshold of one megabyte. If no free space threshold is desired, a
347 346 minfree file containing size 0 can be created.
348 347
|
↓ open down ↓ |
89 lines elided |
↑ open up ↑ |
349 348 Security Issues
350 349 If, upon reboot, the specified savecore directory is not present, it
351 350 will be created prior to the execution of savecore with permissions
352 351 0700 (read, write, execute by owner only) and owner root. It is
353 352 recommended that alternate savecore directories also be created with
354 353 similar permissions, as the operating system crash dump files
355 354 themselves may contain secure information.
356 355
357 356
358 357
359 - April 9, 2015 DUMPADM(1M)
358 + February 13, 2017 DUMPADM(1M)
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX