Bug #9256
closedzfs send space estimation off by > 10% on some datasets
100%
Description
Here is an instance where we see a big discrepancy.
$ zfs send c -e -vvvv domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73 > /tmp/foo 1 delphix staff 470M Jun 22 22:24 /tmp/foo
full send of domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73 estimated size is 411M
total estimated size is 411M
TIME SENT BLOCKS SNAPSHOT
22:24:36 355M 171838 domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73
$ ls -lh /tmp/foo
-rw-r--r-
$
estimate is : 431217656 bytes
actual size is : 492215048 bytes
Without the -e flag, the discrepancy is much higher.
$ zfs send c -vvvv domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73 > /tmp/foo 1 delphix staff 987M Jun 22 22:25 /tmp/foo
full send of domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73 estimated size is 411M
total estimated size is 411M
TIME SENT BLOCKS SNAPSHOT
22:25:47 428M 115392 domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73
22:25:48 817M 196845 domain0/group-117/oracle_db_container-118/oracle_timeflow-119/datafile@oracle_snapshot-73
$ ls -lh /tmp/foo
-rw-r--r-
$
Replication of course always uses the -e and -c flags.
Updated by Electric Monk about 4 years ago
- Status changed from New to Closed
- % Done changed from 0 to 100
git commit df477c0afa111b5205c872dab36dbfde391656de
commit df477c0afa111b5205c872dab36dbfde391656de Author: Paul Dagnelie <pcd@delphix.com> Date: 2018-04-22T23:58:42.000Z 9256 zfs send space estimation off by > 10% on some datasets Reviewed by: Matt Ahrens <matt@delphix.com> Reviewed by: John Kennedy <john.kennedy@delphix.com> Approved by: Richard Lowe <richlowe@richlowe.net>