Author: avg Date: Thu Jun 22 16:58:09 2017 New Revision: 320238 URL: https://svnweb.freebsd.org/changeset/base/320238
Log: MFV r319742: 8056 zfs send size estimate is inaccurate for some zvols illumos/illumos-gate@0255edcc85fc0cd1dda0e49bcd52eb66c06a1b16 https://github.com/illumos/illumos-gate/commit/0255edcc85fc0cd1dda0e49bcd52eb66c06a1b16 https://www.illumos.org/issues/8056 The send size estimate for a zvol can be too low, if the size of the record headers (dmu_replay_record_t's) is a significant portion of the size. This is typically the case when the data is highly compressible, especially with embedded blocks. The problem is that dmu_adjust_send_estimate_for_indirects() assumes that blocks are the size of the "recordsize" property (128KB). However, for zvols, the blocks are the size of the "volblocksize" property (8KB). Therefore, we estimate that there will be 16x less record headers than there really will be. Reviewed by: Matthew Ahrens <mahr...@delphix.com> Reviewed by: Pavel Zakharov <pavel.zakha...@delphix.com> Approved by: Robert Mustacchi <r...@joyent.com> Author: Paul Dagnelie <p...@delphix.com> MFC after: 3 weeks Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Directory Properties: head/sys/cddl/contrib/opensolaris/ (props changed) Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Thu Jun 22 16:52:22 2017 (r320237) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_send.c Thu Jun 22 16:58:09 2017 (r320238) @@ -1140,10 +1140,17 @@ dmu_adjust_send_estimate_for_indirects(dsl_dataset_t * */ uint64_t recordsize; uint64_t record_count; + objset_t *os; + VERIFY0(dmu_objset_from_ds(ds, &os)); /* Assume all (uncompressed) blocks are recordsize. */ - err = dsl_prop_get_int_ds(ds, zfs_prop_to_name(ZFS_PROP_RECORDSIZE), - &recordsize); + 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 { + err = dsl_prop_get_int_ds(ds, + zfs_prop_to_name(ZFS_PROP_RECORDSIZE), &recordsize); + } if (err != 0) return (err); record_count = uncompressed / recordsize; @@ -1212,6 +1219,10 @@ dmu_send_estimate(dsl_dataset_t *ds, dsl_dataset_t *fr err = dmu_adjust_send_estimate_for_indirects(ds, uncomp, comp, stream_compressed, sizep); + /* + * Add the size of the BEGIN and END records to the estimate. + */ + *sizep += 2 * sizeof (dmu_replay_record_t); return (err); } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
