OpenZFS 9256 - zfs send space estimation off by > 10% on some datasets

Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>

Porting Notes:
* Added tuning to man page.
* Test case changes dropped, default behavior unchanged.

OpenZFS-issue: https://www.illumos.org/issues/9256
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/32356b3c56
Closes #7470
This commit is contained in:
Paul Dagnelie 2016-08-26 11:43:21 -07:00 committed by Brian Behlendorf
parent 4ceb8dd6fd
commit ca0845d59e
3 changed files with 27 additions and 3 deletions

View File

@ -1143,6 +1143,17 @@ Maximum number of blocks freed in a single txg.
Default value: \fB100,000\fR.
.RE
.sp
.ne 2
.na
\fBzfs_override_estimate_recordsize\fR (ulong)
.ad
.RS 12n
Record size calculation override for zfs send estimates.
.sp
Default value: \fB0\fR.
.RE
.sp
.ne 2
.na

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@ -69,6 +69,11 @@ int zfs_send_set_freerecords_bit = B_TRUE;
static char *dmu_recv_tag = "dmu_recv_tag";
const char *recv_clone_name = "%recv";
/*
* Use this to override the recordsize calculation for fast zfs send estimates.
*/
unsigned long zfs_override_estimate_recordsize = 0;
#define BP_SPAN(datablkszsec, indblkshift, level) \
(((uint64_t)datablkszsec) << (SPA_MINBLOCKSHIFT + \
(level) * (indblkshift - SPA_BLKPTRSHIFT)))
@ -1360,7 +1365,7 @@ static int
dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
uint64_t compressed, boolean_t stream_compressed, uint64_t *sizep)
{
int err;
int err = 0;
uint64_t size;
/*
* Assume that space (both on-disk and in-stream) is dominated by
@ -1374,7 +1379,9 @@ dmu_adjust_send_estimate_for_indirects(dsl_dataset_t *ds, uint64_t uncompressed,
VERIFY0(dmu_objset_from_ds(ds, &os));
/* Assume all (uncompressed) blocks are recordsize. */
if (os->os_phys->os_type == DMU_OST_ZVOL) {
if (zfs_override_estimate_recordsize != 0) {
recordsize = zfs_override_estimate_recordsize;
} else if (os->os_phys->os_type == DMU_OST_ZVOL) {
err = dsl_prop_get_int_ds(ds,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &recordsize);
} else {
@ -4223,6 +4230,12 @@ dmu_objset_is_receiving(objset_t *os)
}
#if defined(_KERNEL)
/* BEGIN CSTYLED */
module_param(zfs_override_estimate_recordsize, ulong, 0644);
MODULE_PARM_DESC(zfs_override_estimate_recordsize,
"Record size calculation override for zfs send estimates");
/* END CSTYLED */
module_param(zfs_send_corrupt_data, int, 0644);
MODULE_PARM_DESC(zfs_send_corrupt_data, "Allow sending corrupt data");

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@ -37,7 +37,7 @@ verify_runnable "both"
function cleanup
{
for ds in $datasets; do
datasetexists $ds && zfs destroy -rf $ds
destroy_dataset $ds "-rf"
done
}