[bugs] [illumos gate - Bug #1202] (New) "zdb -DD" histogram block count should be decimal-K/M based, not binary

[illumos bugs]

Issue #1202 has been reported by Jim Klimov.

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Bug #1202: "zdb -DD" histogram block count should be decimal-K/M based, not binary
https://www.illumos.org/issues/1202

Author: Jim Klimov
Status: New
Priority: Normal
Assignee: 
Category: zfs - Zettabyte File System
Target version: 
Difficulty: Bite-size
Tags: needs-triage


When I look at the "zdb -DD" output for dedup stats of my pool, I see that large counts of blocks are rolled into 1024-based "kilos" or "megas", which is wrong for this particular data type - they should be 1000-based. 

Example follows: According to "DDT-sha256-zap-unique: 12073552 entries" I should have "12M" (as in twelve million) entries with refcnt=1. Instead, I get "11.5M" which matches "12073552/1024/1024 = 11.514...".
"Sizes", on the other hand, should remain 1024-based.

# zdb -DD -e 1601233584937321596
DDT-sha256-zap-ditto: 359 entries, size 1299 on disk, 205 in core
DDT-sha256-zap-duplicate: 7507179 entries, size 990 on disk, 160 in core
DDT-sha256-zap-unique: 12073552 entries, size 1106 on disk, 178 in core

DDT histogram (aggregated over all DDTs):

bucket              allocated                       referenced          
______   ______________________________   ______________________________
refcnt   blocks   LSIZE   PSIZE   DSIZE   blocks   LSIZE   PSIZE   DSIZE
------   ------   -----   -----   -----   ------   -----   -----   -----
     1    11.5M   1.27T   1.14T   1.16T    11.5M   1.27T   1.14T   1.16T
     2    6.41M    753G    697G    704G    14.1M   1.62T   1.49T   1.51T
     4     646K   47.1G   38.9G   41.4G    2.88M    208G    171G    183G
     8    88.6K   3.63G   2.95G   3.40G     901K   37.5G   30.3G   35.0G
    16    23.7K    432M    282M    434M     491K   8.36G   5.31G   8.41G
    32    5.05K    184M   61.5M   94.2M     217K   8.66G   2.69G   4.05G
    64    1.99K    206M   28.9M   41.8M     149K   14.5G   2.05G   2.99G
   128      416   12.2M   2.09M   5.10M    36.6K   1.02G    183M    454M
   256      182   1.87M    627K   1.89M    28.2K    290M   96.5M    299M
   512       65    834K    208K    711K    22.7K    300M   66.4M    243M
    1K       28    284K     36K    240K    19.9K    176M   24.8M    169M
    2K       22    306K     43K    192K    29.6K    406M   58.7M    257M
    4K        6    258K    258K    288K    18.3K    763M    763M    855M
    8K        2      1K      1K   16.0K    9.33K   4.67M   4.67M   74.6M
   16K        2      1K      1K   24.0K    28.3K   14.2M   14.2M    227M
   64K        2      1K      1K   24.0K     100K   50.1M   50.1M    801M
 Total    18.7M   2.05T   1.86T   1.89T    30.5M   3.16T   2.84T   2.90T

dedup = 1.53, compress = 1.11, copies = 1.02, dedup * compress / copies = 1.67



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