Illumos 4970-4974 - extreme rewind enhancements

4970 need controls on i/o issued by zpool import -XF
4971 zpool import -T should accept hex values
4972 zpool import -T implies extreme rewind, and thus a scrub
4973 spa_load_retry retries the same txg
4974 spa_load_verify() reads all data twice
Reviewed by: Christopher Siden <[email protected]>
Reviewed by: Dan McDonald <[email protected]>
Reviewed by: George Wilson <[email protected]>
Approved by: Robert Mustacchi <[email protected]>

References:
  https://www.illumos.org/issues/4970
  https://www.illumos.org/issues/4971
  https://www.illumos.org/issues/4972
  https://www.illumos.org/issues/4973
  https://www.illumos.org/issues/4974
  https://github.com/illumos/illumos-gate/commit/e42d205

Notes:
    This set of patches adds a set of tunable parameters for the
    "extreme rewind" mode of pool import which allows control over
    the traversal performed during such an import.

Ported by: Tim Chase <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #2598

1 files changed, 46 insertions, 0 deletions

diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5
index 4671c396f..3d7093b73 100644
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -233,6 +233,52 @@ Default value: 24
 .sp
 .ne 2
 .na
+\fBspa_load_verify_data\fR (int)
+.ad
+.RS 12n
+Whether to traverse data blocks during an "extreme rewind" (\fB-X\fR)
+import.  Use 0 to disable and 1 to enable.
+
+An extreme rewind import normally performs a full traversal of all
+blocks in the pool for verification.  If this parameter is set to 0,
+the traversal skips non-metadata blocks.  It can be toggled once the
+import has started to stop or start the traversal of non-metadata blocks.
+.sp
+Default value: 1
+.RE
+
+.sp
+.ne 2
+.na
+\fBspa_load_verify_metadata\fR (int)
+.ad
+.RS 12n
+Whether to traverse blocks during an "extreme rewind" (\fB-X\fR)
+pool import.  Use 0 to disable and 1 to enable.
+
+An extreme rewind import normally performs a full traversal of all
+blocks in the pool for verification.  If this parameter is set to 1,
+the traversal is not performed.  It can be toggled once the import has
+started to stop or start the traversal.
+.sp
+Default value: 1
+.RE
+
+.sp
+.ne 2
+.na
+\fBspa_load_verify_maxinflight\fR (int)
+.ad
+.RS 12n
+Maximum concurrent I/Os during the traversal performed during an "extreme
+rewind" (\fB-X\fR) pool import.
+.sp
+Default value: 10000
+.RE
+
+.sp
+.ne 2
+.na
 \fBzfetch_array_rd_sz\fR (ulong)
 .ad
 .RS 12n