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1 | '\" t |
2 | .\" | |
3 | .\" This file and its contents are supplied under the terms of the | |
4 | .\" Common Development and Distribution License ("CDDL"), version 1.0. | |
5 | .\" You may only use this file in accordance with the terms of version | |
6 | .\" 1.0 of the CDDL. | |
7 | .\" | |
8 | .\" A full copy of the text of the CDDL should have accompanied this | |
9 | .\" source. A copy of the CDDL is also available via the Internet at | |
10 | .\" http://www.illumos.org/license/CDDL. | |
11 | .\" | |
12 | .\" | |
13 | .\" Copyright 2012, Richard Lowe. | |
c06d4368 | 14 | .\" Copyright (c) 2012 by Delphix. All rights reserved. |
dd4769ad RL |
15 | .\" |
16 | .TH "ZDB" "8" "February 15, 2012" "" "" | |
17 | ||
18 | .SH "NAME" | |
19 | \fBzdb\fR - Display zpool debugging and consistency information | |
20 | ||
21 | .SH "SYNOPSIS" | |
22 | \fBzdb\fR [-CumdibcsDvhLXFPA] [-e [-p \fIpath\fR...]] [-t \fItxg\fR] | |
c06d4368 AX |
23 | [-U \fIcache\fR] [-M \fIinflight I/Os\fR] [\fIpoolname\fR |
24 | [\fIobject\fR ...]] | |
dd4769ad RL |
25 | |
26 | .P | |
c06d4368 AX |
27 | \fBzdb\fR [-divPA] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] |
28 | \fIdataset\fR [\fIobject\fR ...] | |
dd4769ad RL |
29 | |
30 | .P | |
c06d4368 AX |
31 | \fBzdb\fR -m [-LXFPA] [-t \fItxg\fR] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] |
32 | \fIpoolname\fR [\fIvdev\fR [\fImetaslab\fR ...]] | |
dd4769ad RL |
33 | |
34 | .P | |
c06d4368 | 35 | \fBzdb\fR -R [-A] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] \fIpoolname\fR |
dd4769ad RL |
36 | \fIvdev\fR:\fIoffset\fR:\fIsize\fR[:\fIflags\fR] |
37 | ||
38 | .P | |
c06d4368 | 39 | \fBzdb\fR -S [-AP] [-e [-p \fIpath\fR...]] [-U \fIcache\fR] \fIpoolname\fR |
dd4769ad RL |
40 | |
41 | .P | |
42 | \fBzdb\fR -l [-uA] \fIdevice\fR | |
43 | ||
44 | .P | |
45 | \fBzdb\fR -C [-A] [-U \fIcache\fR] | |
46 | ||
47 | .SH "DESCRIPTION" | |
48 | The \fBzdb\fR utility displays information about a ZFS pool useful for | |
49 | debugging and performs some amount of consistency checking. It is a not a | |
50 | general purpose tool and options (and facilities) may change. This is neither | |
51 | a fsck(8) nor an fsdb(8) utility. | |
52 | ||
53 | .P | |
54 | The output of this command in general reflects the on-disk structure of a ZFS | |
55 | pool, and is inherently unstable. The precise output of most invocations is | |
56 | not documented, a knowledge of ZFS internals is assumed. | |
57 | ||
58 | .P | |
59 | When operating on an imported and active pool it is possible, though unlikely, | |
60 | that zdb may interpret inconsistent pool data and behave erratically. | |
61 | ||
62 | .SH "OPTIONS" | |
63 | Display options: | |
058ac9ba | 64 | |
058ac9ba | 65 | .sp |
dd4769ad RL |
66 | .ne 2 |
67 | .na | |
68 | \fB-b\fR | |
69 | .ad | |
70 | .sp .6 | |
71 | .RS 4n | |
72 | Display statistics regarding the number, size (logical, physical and | |
73 | allocated) and deduplication of blocks. | |
74 | .RE | |
75 | ||
058ac9ba | 76 | .sp |
dd4769ad RL |
77 | .ne 2 |
78 | .na | |
79 | \fB-c\fR | |
80 | .ad | |
81 | .sp .6 | |
82 | .RS 4n | |
83 | Verify the checksum of all metadata blocks while printing block statistics | |
84 | (see \fB-b\fR). | |
058ac9ba | 85 | .sp |
dd4769ad RL |
86 | If specified multiple times, verify the checksums of all blocks. |
87 | .RE | |
88 | ||
058ac9ba | 89 | .sp |
dd4769ad RL |
90 | .ne 2 |
91 | .na | |
92 | \fB-C\fR | |
93 | .ad | |
94 | .sp .6 | |
95 | .RS 4n | |
96 | Display information about the configuration. If specified with no other | |
97 | options, instead display information about the cache file | |
98 | (\fB/etc/zfs/zpool.cache\fR). To specify the cache file to display, see | |
99 | \fB-U\fR. | |
100 | .P | |
101 | If specified multiple times, and a pool name is also specified display both | |
102 | the cached configuration and the on-disk configuration. If specified multiple | |
103 | times with \fB-e\fR also display the configuration that would be used were the | |
104 | pool to be imported. | |
105 | .RE | |
106 | ||
107 | .sp | |
108 | .ne 2 | |
109 | .na | |
110 | \fB-d\fR | |
111 | .ad | |
112 | .sp .6 | |
113 | .RS 4n | |
114 | Display information about datasets. Specified once, displays basic dataset | |
115 | information: ID, create transaction, size, and object count. | |
116 | .sp | |
117 | If specified multiple times provides greater and greater verbosity. | |
118 | .sp | |
119 | If object IDs are specified, display information about those specific objects only. | |
120 | .RE | |
121 | ||
058ac9ba BB |
122 | .sp |
123 | .ne 2 | |
058ac9ba | 124 | .na |
dd4769ad | 125 | \fB-D\fR |
058ac9ba | 126 | .ad |
dd4769ad RL |
127 | .sp .6 |
128 | .RS 4n | |
129 | Display deduplication statistics, including the deduplication ratio (dedup), | |
130 | compression ratio (compress), inflation due to the zfs copies property | |
131 | (copies), and an overall effective ratio (dedup * compress / copies). | |
132 | .sp | |
133 | If specified twice, display a histogram of deduplication statistics, showing | |
134 | the allocated (physically present on disk) and referenced (logically | |
135 | referenced in the pool) block counts and sizes by reference count. | |
a08ee875 LG |
136 | .sp |
137 | If specified a third time, display the statistics independently for each deduplication table. | |
138 | .sp | |
139 | If specified a fourth time, dump the contents of the deduplication tables describing duplicate blocks. | |
140 | .sp | |
141 | If specified a fifth time, also dump the contents of the deduplication tables describing unique blocks. | |
058ac9ba BB |
142 | .RE |
143 | ||
144 | .sp | |
145 | .ne 2 | |
058ac9ba | 146 | .na |
dd4769ad | 147 | \fB-h\fR |
058ac9ba | 148 | .ad |
dd4769ad RL |
149 | .sp .6 |
150 | .RS 4n | |
151 | Display pool history similar to \fBzpool history\fR, but include internal | |
152 | changes, transaction, and dataset information. | |
058ac9ba BB |
153 | .RE |
154 | ||
155 | .sp | |
156 | .ne 2 | |
058ac9ba | 157 | .na |
dd4769ad | 158 | \fB-i\fR |
058ac9ba | 159 | .ad |
dd4769ad RL |
160 | .sp .6 |
161 | .RS 4n | |
162 | Display information about intent log (ZIL) entries relating to each | |
163 | dataset. If specified multiple times, display counts of each intent log | |
164 | transaction type. | |
058ac9ba BB |
165 | .RE |
166 | ||
058ac9ba | 167 | .sp |
dd4769ad RL |
168 | .ne 2 |
169 | .na | |
170 | \fB-l\fR \fIdevice\fR | |
171 | .ad | |
172 | .sp .6 | |
173 | .RS 4n | |
174 | Display the vdev labels from the specified device. If the \fB-u\fR option is | |
175 | also specified, also display the uberblocks on this device. | |
176 | .RE | |
177 | ||
178 | .sp | |
179 | .ne 2 | |
180 | .na | |
181 | \fB-L\fR | |
182 | .ad | |
183 | .sp .6 | |
184 | .RS 4n | |
185 | Disable leak tracing and the loading of space maps. By default, \fBzdb\fR | |
186 | verifies that all non-free blocks are referenced, which can be very expensive. | |
187 | .RE | |
188 | ||
189 | .sp | |
190 | .ne 2 | |
191 | .na | |
192 | \fB-m\fR | |
193 | .ad | |
194 | .sp .6 | |
195 | .RS 4n | |
196 | Display the offset, spacemap, and free space of each metaslab. | |
197 | When specified twice, also display information about the maximum contiguous | |
198 | free space and the percentage of free space in each space map. When specified | |
199 | three times display every spacemap record. | |
200 | .RE | |
201 | ||
202 | .sp | |
203 | .ne 2 | |
204 | .na | |
205 | \fB-R\fR \fIpoolname\fR \fIvdev\fR:\fIoffset\fR:\fIsize\fR[:\fIflags\fR] | |
206 | .ad | |
207 | .sp .6 | |
208 | .RS 4n | |
209 | Read and display a block from the specified device. By default the block is | |
210 | displayed as a hex dump, but see the description of the \'r\' flag, below. | |
211 | .sp | |
212 | The block is specified in terms of a colon-separated tuple \fIvdev\fR (an | |
213 | integer vdev identifier) \fIoffset\fR (the offset within the vdev) \fIsize\fR | |
214 | (the size of the block to read) and, optionally, \fIflags\fR (a set of flags, | |
215 | described below). | |
216 | ||
217 | .sp | |
218 | .ne 2 | |
219 | .na | |
220 | \fBb\fR \fIoffset\fR | |
221 | .ad | |
222 | .sp .6 | |
223 | .RS 4n | |
224 | Print block pointer | |
225 | .RE | |
226 | ||
227 | .sp | |
228 | .ne 2 | |
229 | .na | |
230 | \fBd\fR | |
231 | .ad | |
232 | .sp .6 | |
233 | .RS 4n | |
234 | Decompress the block | |
235 | .RE | |
236 | ||
237 | .sp | |
238 | .ne 2 | |
239 | .na | |
240 | \fBe\fR | |
241 | .ad | |
242 | .sp .6 | |
243 | .RS 4n | |
244 | Byte swap the block | |
245 | .RE | |
246 | ||
247 | .sp | |
248 | .ne 2 | |
249 | .na | |
250 | \fBg\fR | |
251 | .ad | |
252 | .sp .6 | |
253 | .RS 4n | |
254 | Dump gang block header | |
255 | .RE | |
256 | ||
257 | .sp | |
258 | .ne 2 | |
259 | .na | |
260 | \fBi\fR | |
261 | .ad | |
262 | .sp .6 | |
263 | .RS 4n | |
264 | Dump indirect block | |
265 | .RE | |
266 | ||
267 | .sp | |
268 | .ne 2 | |
269 | .na | |
270 | \fBr\fR | |
271 | .ad | |
272 | .sp .6 | |
273 | .RS 4n | |
274 | Dump raw uninterpreted block data | |
275 | .RE | |
276 | .RE | |
277 | ||
278 | .sp | |
279 | .ne 2 | |
280 | .na | |
281 | \fB-s\fR | |
282 | .ad | |
283 | .sp .6 | |
284 | .RS 4n | |
285 | Report statistics on \fBzdb\fR\'s I/O. Display operation counts, bandwidth, | |
286 | and error counts of I/O to the pool from \fBzdb\fR. | |
287 | .RE | |
288 | ||
289 | .sp | |
290 | .ne 2 | |
291 | .na | |
292 | \fB-S\fR | |
293 | .ad | |
294 | .sp .6 | |
295 | .RS 4n | |
296 | Simulate the effects of deduplication, constructing a DDT and then display | |
297 | that DDT as with \fB-DD\fR. | |
298 | .RE | |
299 | ||
300 | .sp | |
301 | .ne 2 | |
302 | .na | |
303 | \fB-u\fR | |
304 | .ad | |
305 | .sp .6 | |
306 | .RS 4n | |
307 | Display the current uberblock. | |
308 | .RE | |
309 | ||
310 | .P | |
311 | Other options: | |
312 | ||
313 | .sp | |
314 | .ne 2 | |
315 | .na | |
316 | \fB-A\fR | |
317 | .ad | |
318 | .sp .6 | |
319 | .RS 4n | |
320 | Do not abort should any assertion fail. | |
321 | .RE | |
322 | ||
323 | .sp | |
324 | .ne 2 | |
325 | .na | |
326 | \fB-AA\fR | |
327 | .ad | |
328 | .sp .6 | |
329 | .RS 4n | |
330 | Enable panic recovery, certain errors which would otherwise be fatal are | |
331 | demoted to warnings. | |
332 | .RE | |
333 | ||
334 | .sp | |
335 | .ne 2 | |
336 | .na | |
337 | \fB-AAA\fR | |
338 | .ad | |
339 | .sp .6 | |
340 | .RS 4n | |
341 | Do not abort if asserts fail and also enable panic recovery. | |
342 | .RE | |
343 | ||
344 | .sp | |
345 | .ne 2 | |
346 | .na | |
347 | \fB-e\fR [-p \fIpath\fR]... | |
348 | .ad | |
349 | .sp .6 | |
350 | .RS 4n | |
351 | Operate on an exported pool, not present in \fB/etc/zfs/zpool.cache\fR. The | |
352 | \fB-p\fR flag specifies the path under which devices are to be searched. | |
353 | .RE | |
354 | ||
355 | .sp | |
356 | .ne 2 | |
357 | .na | |
358 | \fB-F\fR | |
359 | .ad | |
360 | .sp .6 | |
361 | .RS 4n | |
362 | Attempt to make an unreadable pool readable by trying progressively older | |
363 | transactions. | |
364 | .RE | |
365 | ||
c06d4368 AX |
366 | .sp |
367 | .ne 2 | |
368 | .na | |
369 | \fB-M \fIinflight I/Os\fR \fR | |
370 | .ad | |
371 | .sp .6 | |
372 | .RS 4n | |
373 | Limit the number of outstanding checksum I/Os to the specified value. The | |
374 | default value is 200. This option affects the performance of the \fB-c\fR | |
375 | option. | |
376 | .RE | |
377 | ||
dd4769ad RL |
378 | .sp |
379 | .ne 2 | |
380 | .na | |
381 | \fB-P\fR | |
382 | .ad | |
383 | .sp .6 | |
384 | .RS 4n | |
385 | Print numbers in an unscaled form more amenable to parsing, eg. 1000000 rather | |
386 | than 1M. | |
387 | .RE | |
388 | ||
389 | .sp | |
390 | .ne 2 | |
391 | .na | |
392 | \fB-t\fR \fItransaction\fR | |
393 | .ad | |
394 | .sp .6 | |
395 | .RS 4n | |
396 | Specify the highest transaction to use when searching for uberblocks. See also | |
397 | the \fB-u\fR and \fB-l\fR options for a means to see the available uberblocks | |
398 | and their associated transaction numbers. | |
399 | .RE | |
400 | ||
401 | .sp | |
402 | .ne 2 | |
403 | .na | |
404 | \fB-U\fR \fIcachefile\fR | |
405 | .ad | |
406 | .sp .6 | |
407 | .RS 4n | |
c06d4368 | 408 | Use a cache file other than \fB/etc/zfs/zpool.cache\fR. |
dd4769ad RL |
409 | .RE |
410 | ||
411 | .sp | |
412 | .ne 2 | |
413 | .na | |
414 | \fB-v\fR | |
415 | .ad | |
416 | .sp .6 | |
417 | .RS 4n | |
418 | Enable verbosity. Specify multiple times for increased verbosity. | |
419 | .RE | |
420 | ||
421 | .sp | |
422 | .ne 2 | |
423 | .na | |
424 | \fB-X\fR | |
425 | .ad | |
426 | .sp .6 | |
427 | .RS 4n | |
428 | Attempt \'extreme\' transaction rewind, that is attempt the same recovery as | |
429 | \fB-F\fR but read transactions otherwise deemed too old. | |
430 | .RE | |
431 | ||
432 | .P | |
433 | Specifying a display option more than once enables verbosity for only that | |
434 | option, with more occurrences enabling more verbosity. | |
435 | .P | |
436 | If no options are specified, all information about the named pool will be | |
437 | displayed at default verbosity. | |
438 | ||
439 | .SH "EXAMPLES" | |
058ac9ba | 440 | .LP |
dd4769ad RL |
441 | \fBExample 1 \fRDisplay the configuration of imported pool 'rpool' |
442 | .sp | |
443 | .in +2 | |
444 | .nf | |
445 | # zdb -C rpool | |
446 | ||
447 | MOS Configuration: | |
448 | version: 28 | |
449 | name: 'rpool' | |
450 | ... | |
451 | .fi | |
452 | .in -2 | |
453 | .sp | |
454 | ||
455 | .LP | |
456 | \fBExample 2 \fRDisplay basic dataset information about 'rpool' | |
457 | .sp | |
458 | .in +2 | |
459 | .nf | |
460 | # zdb -d rpool | |
461 | Dataset mos [META], ID 0, cr_txg 4, 26.9M, 1051 objects | |
462 | Dataset rpool/swap [ZVOL], ID 59, cr_txg 356, 486M, 2 objects | |
463 | ... | |
464 | .fi | |
465 | .in -2 | |
466 | .sp | |
467 | ||
468 | .LP | |
2016ff96 BB |
469 | \fBExample 3 \fRDisplay basic information about object 0 |
470 | in 'rpool/export/home' | |
dd4769ad RL |
471 | .sp |
472 | .in +2 | |
473 | .nf | |
474 | # zdb -d rpool/export/home 0 | |
475 | Dataset rpool/export/home [ZPL], ID 137, cr_txg 1546, 32K, 8 objects | |
476 | ||
477 | Object lvl iblk dblk dsize lsize %full type | |
478 | 0 7 16K 16K 15.0K 16K 25.00 DMU dnode | |
479 | .fi | |
480 | .in -2 | |
481 | .sp | |
482 | ||
483 | .LP | |
484 | \fBExample 4 \fRDisplay the predicted effect of enabling deduplication on 'rpool' | |
485 | .sp | |
486 | .in +2 | |
487 | .nf | |
488 | # zdb -S rpool | |
489 | Simulated DDT histogram: | |
490 | ||
491 | bucket allocated referenced | |
492 | ______ ______________________________ ______________________________ | |
493 | refcnt blocks LSIZE PSIZE DSIZE blocks LSIZE PSIZE DSIZE | |
494 | ------ ------ ----- ----- ----- ------ ----- ----- ----- | |
495 | 1 694K 27.1G 15.0G 15.0G 694K 27.1G 15.0G 15.0G | |
496 | 2 35.0K 1.33G 699M 699M 74.7K 2.79G 1.45G 1.45G | |
497 | ... | |
498 | dedup = 1.11, compress = 1.80, copies = 1.00, dedup * compress / copies = 2.00 | |
499 | .fi | |
500 | .in -2 | |
501 | .sp | |
502 | ||
503 | .SH "SEE ALSO" | |
504 | zfs(8), zpool(8) |